Liquid recovery filter

ABSTRACT

A liquid recovery filter assembly for recovering filtered liquid trapped within a core or downstream side of a filter element. Multiple embodiments each include a recovery port and a recovery filter in fluid communication with the core or downstream side of the filter element. The recovery port is opened following filtration operations to permit and to facilitate filtered liquid to flow from a downstream or outlet port, thus allowing recovery of liquid remaining in the filter core or downstream side following filtering operations. The recovery filter permits the introduction of pressurized gas to force the filtered liquids from the filter assembly without compromising the sterility and/or non-contaminant condition of the liquid. Additional aspects include exchangeable filter cartridges or filter elements in single and multi-round configurations, embodiments with aspiration tubes and dip tubes and still others with hydrophilic/hydrophobic recovery filters that function as filters and as valves for the recovery port.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. Regular Utilityapplication Ser. No. 14/521,437, filed Oct. 22, 2014, now U.S. Pat. No.9,861,916, which is a continuation-in-part of U.S. Ser. No. 13/460,583filed Apr. 30, 2012, now U.S. Pat. No. 9,757,666, and PCT ApplicationSerial No. PCT/US13/37671 filed 23 Apr. 2013, the contents all of whichare incorporated in their entirety herein by reference. This applicationalso claims the benefit of U.S. Provisional Application Ser. No.61/992,029 filed May 12, 2014, as a Divisional Application of the Ser.No. 14/521,437 Application that claimed and received the same benefit,the contents of which also are incorporated in their entirety herein byreference.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure relates generally to filtration devices andsystems, and particularly to liquid recovery filter assemblies havinginlet and outlet ports and, in some embodiments, vent, drain and/orrecovery ports for the drainage and recovery of filtered liquids fromthe filter housing and enclosed filter after filtering operations. Moreparticularly, the disclosure relates to apparatus and methods toretrieve liquids retained in filtration apparatus after filtrationprocesses.

2. Description of the Related Art

Innumerable filtration devices and systems have been developed for thecleaning and purification of a wide range of gases and liquids. One areathat requires extremely high quality filtration is in the field ofpharmaceutical manufacture, where a number of different liquids areinvolved in the manufacturing processes of a large number of drugs andmedications. These various liquids are often quite costly to produce,and as a result, much effort and expense is expended to recover suchliquids in a sterile manner during the manufacturing process, insofar aspracticable.

During liquid filtration processes, liquid is passed through the filterassembly(s) and the filtered liquid is recovered from the downstream oroutlet side of the enclosed filter element. In one type of filterelement used, the filter element conventionally has a generally toroidalconfiguration wherein the unfiltered liquid passes through the filterelement from outside the filter and through the filter material to ahollow inner core. Other filter element configurations may also be usedin a similar manner or in a reverse manner flowing from the inner coreto the outside of the element. One problem with such filterconfigurations is that when the filtration process is completed, thereis a volume of purified, filtered liquid still resident in the filterelement, as well as unfiltered liquid remaining within the filterhousing and outside the filter element. These liquids are often quitevaluable, as noted above. Discarding these liquids when the filtrationprocess is completed or interrupted results in the loss of aconsiderable amount of valuable and usable liquid, particularly afternumerous filtration processes.

One method used to remove the resident filtered liquids is to introducepressurized gas into the system to force the liquids out of the filterassembly. This approach, although effective, is problematic due to therelatively high bubble points of the filter materials used for manyspecific applications, including many of the filtration processes commonin the pharmaceutical industry. When the filtration material of thefilter element is wetted (as is typically the case after use for liquidprocessing), bulk gas flow through the filter element is blocked by thewetted filter material at pressures below the bubble point pressure, asis commonly known in the art. Therefore, gas pressurized to pressuresbelow the bubble point pressure cannot efficiently clear the downstream(filtered) liquid.

Filter materials with pore sizes about and below 0.2 microns haveparticularly high bubble point pressures that require relatively highgas pressures (typically greater than 40 psi for membrane-basedabsolute-rated filters wet with water or other liquid of similar surfacetension) to evacuate the liquid in the wetted filter material. Evenfilter materials with pore sizes greater than 0.2 microns can havebubble points higher than the pressure limits of other components thatcommonly make up filter assemblies. The introduction of high pressuregas can compromise the physical and functional integrity of the filterelement and/or filter assembly by, for example, causing the filterelement to separate from its attachment points, or causing the filterelement to physically break and potentially compromise the desiredseparation of unfiltered and filtered liquids, allowing them to mixdownstream. Mixture of the filtered and unfiltered liquids wouldinvariably compromise the intended purity or sterility of the filteredliquid. In addition, assemblies using, for example, barbed connectorsfor hoses can experience hose breakage or separation from the barbedconnectors when gas at a relatively high pressure is introduced into thefiltering apparatus. Moreover, pressure-sensitive components such asthose incorporating thin films have pressure ratings and operationallimits well below the bubble points of many filter materials.

What is needed is a filter recovery system that provides a means toremove valuable filtered liquids from a filter apparatus in a sterile orotherwise contamination-free manner. What is also needed is a filterrecovery system that permits the use of a gas applied at a relativelylow pressure to effectively remove resident filtered liquids whilemaintaining the sterility and/or any other required characteristics ofthe liquids in the downstream locations within, and external to (furtherdownstream of), a filter assembly. These and other problems are solvedby the disclosed liquid recovery filter apparatus as shown and describedin the appended drawings, disclosure summary, and more particularly inthe detailed description of the disclosure.

SUMMARY OF THE DISCLOSURE

The liquid recovery filter assembly disclosed herein comprises a numberof embodiments, wherein each of the embodiments includes a filterhousing or shell containing a filter element secured therein. All of theembodiments have an inlet port that extends into the upstream or inletside of the housing, and an outlet port extending from the downstream oroutlet side of the housing. The terms “inlet side,” “upstream,”“upstream side,” and similar terms all refer to the section or volume ofthe filter assembly located on the inlet portion of the apparatus, i.e.,the portion of the filter assembly that may contain unfiltered liquidduring operation. The terms “outlet side,” “downstream,” “downstreamside,” and similar terms all refer to the sections or volumes of thefilter assembly located within the core of the filter element(s) forfilter elements having a core and with an outside-in flow path, sectionsor volumes of the filter assembly located at a downstream end or on aside of the filter element that contains filtered liquid that has passedthrough the filter element during operation of the filter assembly, orin components, e.g., tubes and connectors, downstream of the filter coreand the filter assembly.

For all embodiments, the demarcation or boundary between “upstream,”i.e., “unfiltered” liquid and “downstream,” i.e., “filtered” liquid isthe filter element constructed from filtration material and anyassociated non-porous filter element features including, but not limitedto, filter cartridge end caps, end cap adaptors, sealing mechanisms andthe like used to define and connect the filter element to the filterassembly housing. More particularly, “upstream” is defined anddemarcated by an upstream designated surface of the filtration materialand any associated non-porous filter element feature. Likewise,“downstream” is defined and demarcated by a downstream designatedsurface of the filtration material and any associated non-porous filterelement features. Any liquids resident in the filter apparatus upstreamof the “upstream” surface of the filtration material shall be considered“unfiltered liquid” for the purposes of this disclosure. Any liquidsresident in the filter apparatus downstream of the “downstream” surfaceof the filtration material shall be considered “filtered liquid” forpurposes of this disclosure. Any liquids resident in the filterapparatus contained between the upstream surface and the downstreamsurface of the filtration material shall be considered “filtrationmaterial holdup” for purposes of this disclosure. As used herein,“filter material” and/or “filtration material” shall mean any filtermembrane, filter media, or any other material or substance used tofilter fluids including liquids and gases. The filter assembliesdisclosed herein are constructed so that essentially all liquidintroduced into any embodiment of the filter assemblies will passthrough the filter element from the designated inlet port to thedesignated outlet port of the filter assembly.

The filter housing or shell may also have upstream or inlet side ventsor passages, and/or upstream or inlet side drain ports or passages.These optional upstream ports or passages allow the upstream portion ofthe filter housing to be drained of unfiltered liquid, i.e., liquid thathas not passed through the filter element from the upstream or inletside to the downstream or outlet side of the filter element during afiltration operation. These ports are also used to remove gas trapped onthe upstream side of the filter membrane, to monitor pressure, toperform integrity tests, and for other purposes as are commonly known inthe art.

Each of the liquid recovery filter embodiments may further includedownstream or outlet side ports or passages in addition to the primaryoutlet port that communicate liquidly with the downstream core, ordownstream end/side of the filter element. These downstream or outletports are normally closed during filtering operations, but may be openedin some applications to remove air bubbles or when the filtrationoperation has been completed. The opening of these downstream portsallows air or other gas to flow into the core or downstream end/side ofthe filter element, thus “breaking the seal” or hydraulic lock commonlyformed within the core, or downstream side, of the filter element. Insome currently available filter assemblies, this allows the valuablefiltered liquid contained within the core or downstream side of thefilter element to flow from the filter assembly. Exposure to theenvironment external to the filter assembly, however, through openeddownstream ports commonly present in related art filter assemblies, maybring unwanted contamination that if brought in contact with a batch offiltered product, could compromise the batch. The embodiments disclosedherein provide filter assembly constructions that permit recovery offiltered liquid from the downstream side and prevent the contaminationof downstream filtered liquids.

Two basic configurations of the liquid recovery filter are disclosedherein (along with several additional embodiments of each), one having adownstream or outlet port disposed at the bottom of the filter assembly,and the other having a downstream or outlet port disposed at or near thetop of the assembly. The second of these configurations includes a diptube (extending internally from the outlet port) to allow liquid to flowfrom the bottom of the core, or bottom of the downstream side of thefilter element and out of the outlet port for recovery. The first basicconfiguration, i.e., having the primary outlet port or passage disposedbelow the filter element, includes embodiments that differ due to thedifferent locations or arrangements of the primary inlet and outletports or passages. The second basic configuration, i.e., having theprimary outlet port or passage extending from the top or upper portionof the filter assembly, includes additional embodiments that also differdue to the different arrangements of the primary inlet and outlet portsor passages. All of the embodiments disclosed herein include means forrecovering filtered liquid from the core or downstream side of thefilter element aseptically and/or without contamination of the filteredliquid.

Also disclosed are port/valve configurations, settings and portassignments that permit liquid to be introduced into the filterassemblies in a reverse direction with the reassignment of inlet,outlet, vent, drain, and recovery ports to remove the resident filteredliquids in a sterile or contamination-free manner from the apparatusafter a filtering event. In these configurations, what would beconsidered downstream elements are reassigned as upstream elements andwhat would be considered upstream elements are reassigned as downstreamelements. It should be understood that a recovery filter should besecured to any port that will function as, and be assigned as, adownstream recovery port. As used herein, “recovery port” is defined asa port that allows sterile or otherwise contaminant-free gas to beintroduced into the liquid recovery filter assembly from an externalsource into the downstream side of the filter assembly.

In a further aspect of the disclosure, an aspiration tube isincorporated into the downstream side of the filter assembly and extendsout of the housing to form a recovery port. The tube can be formed toextend into a lower end of the assembly or filter element, or may extendthrough the filter element core to a point proximal to an upper end ofthe filter element and any length in between these two extremes. Forfilter assembly embodiments with multiple enclosed filter elements, eachelement has a dedicated aspiration tube. The tubes may be joined via amanifold to share a single recovery port and inline air filter, or mayhave dedicated recovery ports and inline air filters among some of thedisclosed embodiments.

In a still further aspect of the disclosure, single and multi-roundfilter assemblies include replaceable filter cartridges. The filterassembly housings may include removable sections (such as a lid, endcap, removable bowl, access panel, etc.) to permit entry into theassemblies to remove and replace used filter cartridges. The filterhousings include receiving walls or posts to secure the filtercartridges in the housings. These embodiments may also includeaspiration tubes to assist the liquid recovery function to forcefiltered liquids from the filter assemblies.

In a yet further aspect of the disclosure, a hydrophobic or combinationhydrophilic/hydrophobic filter is secured in an end cap or otherlocation on a filter cartridge to permit aseptic or contamination-freeremoval of filtered liquids remaining in the filter assembly after afiltration operation with the use of gases introduced under pressure.The combination hydrophilic/hydrophobic filter provides a dual functionto filter gases introduced into the filter assemblies and to act as avalve to eliminate the need for a recovery port and a mechanical valve.In some embodiments, however, the hydrophilic/hydrophobic filter couldbe attached to a recovery port with or without a mechanical valve.

These and other features of the present disclosure will become readilyapparent upon further review of the following drawings and detaileddisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of a first embodiment of a liquidrecovery filter according to one aspect of the disclosure, illustratingits general external configuration.

FIG. 2 is an elevation view in section of a liquid recovery filteraccording to another aspect of the disclosure having a generally inlineflow path, illustrating its internal configuration.

FIG. 3 is an elevation view in section of a liquid recovery filteraccording to a further aspect of the disclosure having a generallyC-shaped flow path, illustrating its internal configuration.

FIG. 4 is an elevation view in section of a liquid recovery filteraccording to a still further aspect of the disclosure having a generallyL-shaped flow path, illustrating its internal configuration.

FIG. 5 is an elevation view in section of a liquid recovery filteraccording to yet another aspect of the disclosure having a generallyT-shaped flow path, illustrating its internal configuration.

FIG. 6 is an elevation view in section of a liquid recovery filteraccording to another aspect of the disclosure having a generallyS-shaped flow path, illustrating its internal configuration.

FIG. 7 is a front top perspective view of a liquid recovery filterassembly according to the embodiment shown in FIG. 4.

FIG. 8 is a front top perspective view of a liquid recovery filterassembly according to the embodiment shown in FIG. 3

FIG. 9 is a front top perspective view of a liquid recovery filterassembly according to the embodiment shown in FIG. 5.

FIG. 10 is a front top perspective view of a liquid recovery filterassembly according to the embodiment shown in FIG. 2.

FIG. 11 is a side view in elevation of the liquid recovery filterassembly shown in FIGS. 4 and 7.

FIG. 12 is a side sectional view of the liquid recovery filter assemblyshown in FIGS. 4, 7 and 11.

FIG. 13 is a front top perspective view of a liquid recovery filterassembly according to the embodiment shown in FIGS. 4, 7, 11 and 12.

FIG. 14 is a sectional view in elevation of a single-round liquidrecovery filter assembly with an aspiration tube according to anotheraspect of the disclosure.

FIG. 15 is a sectional view in elevation of a multi-round liquidrecovery filter assembly with aspiration tubes according to a furtheraspect of the disclosure.

FIG. 16 is a sectional view of a liquid recovery filter assembly with afilter cartridge shown in perspective with a hydrophobic/hydrophilicfilter insert according to a still further aspect of the disclosure.

FIG. 17 is a sectional view in elevation of a single-round liquidrecovery filter assembly with an aspiration tube according to yetanother aspect of the disclosure.

FIG. 18 is a sectional view in elevation of a multi-round liquidrecovery filter assembly with aspiration tubes according to a yetfurther aspect of the disclosure.

FIG. 19 is a sectional view in elevation of a multi-round liquidrecovery filter assembly with aspiration tubes according to a stillfurther aspect of the disclosure.

FIG. 20 is a sectional view in elevation of a multi-round liquidrecovery filter assembly with aspiration tubes according to stillanother aspect of the disclosure.

FIG. 21 is a sectional view in elevation of a single-round liquidrecovery filter assembly with a double open ended filter cartridgeaccording to yet another aspect of the disclosure.

FIG. 22 is a sectional view in elevation of a multi-round liquidrecovery filter assembly with double open ended filter cartridgesaccording to still another aspect of the disclosure.

FIG. 23 is a sectional view in elevation of a liquid recovery assemblywith a dip tube according to a still further embodiment of thedisclosure.

FIG. 24 is a sectional view of a combination hydrophobic/hydrophilicpleated membrane according to another embodiment of the disclosure.

FIG. 25 is a bottom perspective view of a filter cartridge according toone embodiment of the disclosure.

FIG. 26 is a bottom perspective view of a filter cartridge according toa further embodiment of the disclosure.

FIG. 27 is a side perspective view of a dual layerhydrophobic/hydrophilic membrane according to another aspect of thedisclosure.

FIG. 28 is a side perspective view of a hydrophilic/hydrophobic membraneembedded into a membrane according to a further aspect of thedisclosure.

FIG. 29 is a sectional view in elevation of an “L” shaped liquidrecovery assembly with a secondary valve positioned between the assemblyhousing and a recovery filter according to an aspect of the disclosure.

FIG. 30 is a sectional view in elevation of a “T” shaped liquid recoveryassembly with a secondary valve positioned between the assembly housingand a recovery filter according to a different aspect of the disclosure.

FIG. 31 is a sectional view in elevation of an “L” shaped liquidrecovery assembly with a secondary valve positioned between the assemblyhousing and a recovery filter with an upstream drain port and anupstream vent port according to yet another aspect of the disclosure.

FIG. 32 is a sectional view in elevation of a “T” shaped liquid recoveryassembly with a secondary valve positioned between the assembly housingand a recovery filter with an upstream drain port and an upstream ventport according to yet another aspect of the disclosure.

FIG. 33 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a collapsible valve with a screw-typeshutoff in an open position according to yet another aspect of thedisclosure.

FIG. 34 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a collapsible valve with a screw-typeshutoff in a closed position according to still another aspect of thedisclosure.

FIG. 35 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a collapsible valve with a lever-typeshutoff in an open position according to a further aspect of thedisclosure.

FIG. 36 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a collapsible valve with a lever-typeshutoff in a closed position according to a further aspect of thedisclosure.

FIG. 37 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a collapsible one-way valve accordingto a yet further aspect of the disclosure.

FIG. 38 is a partial sectional view in elevation and in partial phantomof a liquid recovery assembly with a membrane one-way valve according toa still further aspect of the disclosure.

FIG. 39 is a partial sectional view in partial phantom of a membranevalve according to the embodiment of the disclosure shown in FIG. 38.

FIG. 40 is a side sectional view in elevation and in partial phantom ofa liquid recovery assembly with a concentrically arranged outlet andrecovery port according to yet another aspect of the disclosure.

FIG. 41 is a side sectional view of a liquid recovery assembly with arecovery filter secured inside the assembly housing according to stillanother aspect of the disclosure.

FIG. 42 is a side view in elevation of the liquid recovery assemblyshown in FIG. 41.

FIG. 43 is a side sectional view in elevation and in partial phantom ofa line clearing filter inlet/outlet assembly according to a furtheraspect of the disclosure.

FIG. 44 is a side sectional view in elevation and in partial phantom ofa line clearing filter inlet/outlet assembly with a valve according to ayet further aspect of the disclosure.

FIG. 45 is a side sectional view in elevation and in partial phantom ofa line clearing filter inlet/outlet assembly with an upstream recoveryvalve and a downstream recovery valve according to a still furtheraspect of the disclosure.

FIG. 46 is a side sectional view of the liquid recovery assembly shownin FIGS. 41 and 42.

FIG. 47 is a side sectional view of the vent port bleed valve of theliquid recovery assembly shown in FIGS. 41 and 42 in an open position.

FIG. 48 is a side sectional view of the vent port bleed valve shown inFIG. 47 in a closed position.

FIG. 49 is a side sectional view of a recovery filter subassemblyaccording to the embodiment of the disclosure shown in FIGS. 41 and 42.

FIG. 50 is a side sectional view of a filter assembly with an enclosedrecovery filter subassembly and a processing filter secured in thehousing via O-ring attachment according to an embodiment of thedisclosure.

FIG. 51 is a side sectional view of a filter assembly with an enclosedrecovery filter subassembly and a processing filter permanently securedto the filter assembly housing according to another embodiment of thedisclosure.

FIG. 52 is a side sectional view of a filter assembly with a processingfilter secured in the housing with O-rings according to a furtherembodiment of the disclosure.

FIG. 53 is a side view of a vent port valve subassembly in an openposition according to the embodiment of the disclosure shown in FIGS. 41and 42.

FIG. 54 is a side view of the vent port valve subassembly shown in FIG.53 with the valve in a closed position.

FIG. 55 is a side sectional view of a drain port valve subassembly in anopen position according to the embodiment of the disclosure shown inFIGS. 41 and 42.

FIG. 56 is a side sectional view of the drain port valve subassemblyshown in FIG. 55 with the valve in a closed position.

FIG. 57 is a top view of a cross-section of the bottom half of thefilter assembly shown in FIG. 50.

FIG. 58 is a top view of a cross-section of a filter assembly accordingto another embodiment of the disclosure.

FIG. 59 is a side sectional view of the recovery port bleed valve of theliquid recovery assembly shown in FIGS. 41 and 42 in an open position.

FIG. 60 is a side sectional view of the recovery port bleed valve shownin FIG. 59 in a closed position.

FIG. 61 is a side view of a recovery port valve subassembly in an openposition according to the embodiment of the disclosure shown in FIGS. 41and 42.

FIG. 62 is a side view of the recovery port valve subassembly shown inFIG. 61 with the valve in a closed position.

FIG. 63 is a side sectional view of an internal recovery filtersubassembly with an upper attachment post secured with an O-ring sealand a lower attachment post permanently secured to a filter elementaccording to one embodiment of the disclosure.

FIG. 64 is a side sectional view of an internal recovery filtersubassembly with an upper attachment post permanently secured to afilter housing upper end cap and a lower attachment post secured with anO-ring seal to a filter element according to another embodiment of thedisclosure.

FIG. 65 is a side sectional view of an internal recovery filtersubassembly with an upper attachment post and a lower attachment postboth permanently secured to a housing assembly upper end cap and afilter element, respectively, according to a further embodiment of thedisclosure.

It should be understood that similar reference characters denotecorresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

The liquid recovery filter comprises several embodiments, eachconfigured for the recovery of liquids within the filter capsule, filterhousing, the filter element, and any attached downstream components,e.g., tubes and connectors, downstream of the filter core and the filterassembly after the completion of filtration operations, e.g., when abatch has been filtered and/or the filter element is to be changed, etc.It should be understood that the filter capsule or housing embodimentsmay be constructed as permanently sealed structures (with the exceptionof their various ports or passages), or constructed as reusable unitswith removable end caps and/or multi-piece housings, permitting accessto the filter element therein for replacement or cleaning and reuse, ormay be configured as replaceable modular units having pre-installedfilter elements.

Referring to FIG. 1, a liquid recovery filter assembly is showndesignated generally as 110. Filter assembly 110 includes a filterhousing or shell designated generally as 111 having a shell wall 112with an upper end 114 and an opposite lower end 116, both secured to, orintegral with, shell wall 112 that may be substantially cylindrical inone embodiment. As used herein, relative terms “upper” and “lower” areused as component designations to define the spatial orientation ofcomponents based on the influence of gravity on the direction of liquidflow in the filter assemblies with gravitationally influenced flowdefined as going from an upper end to a lower end. It should beunderstood that any of the filter assembly embodiments disclosed hereinmay be oriented in multiple spatial orientations, e.g., upside down andsideways relative to the orientation shown in any figure, wherein thedifferent orientations may reverse or alter the functional meaning ofthe “upper” and “lower” designations without altering the relativeorientation and cooperation of the various filer assembly components.Filter assembly 110 may be oriented as shown in FIG. 1, with inlet end114 disposed above outlet end 116. It should be understood theorientation can vary and be reversed as needed for a particularapplication.

Filter assembly 110 includes an upstream or inlet port 118, and agenerally opposite downstream or outlet port 120 for the flow of liquidto and from the device. A recovery port 122, apart from its function inthis disclosure to maximize recovery of filtered liquids from the filterassembly, may function as a vent to the outlet or downstream side of afilter element secured in the filter assembly (as disclosed below). Anupstream vent port 124 extends from upper end 114 and is in fluidcommunication with an upstream internal volume of the filter assemblydefined as being between housing 111 and an upstream designated surfaceof the filter element therein. An upstream drain port 126 extends fromlower end 116 and can be used to drain liquids from the upstream side ofthe enclosed filter element, i.e., the upstream internal volume definedabove.

All of the liquid recovery device embodiments disclosed herein includecombinations or sub-combinations of these various vents, ports, andpassages. However, the relationship and orientation of the variousvents, ports, and passages are arranged differently in differentembodiments. Some embodiments relative to others include one or moreadditional ports or passages to accommodate specific arrangements,orientations and functions of the other ports and passages. It should beunderstand that all ports may be configured with adaptors to allowconnection to a tube, pipe, sub-assembly, equipment, etc. These adaptorscan be of any type including, but not limited to, barbed, threaded,gasket and clamp, quick connect, compression-type, as well as any otheradaptor disclosed herein and/or known in the art. Moreover, theoperational states and settings of the ports and associated valves(disclosed further herein) may be varied and ports reassigned functionto permit the reverse flow of liquid through the assembly embodiments.

The locations and orientations of the various ports 118 through 126 mostclosely resemble the configuration of the liquid recovery filterembodiment shown in FIG. 4, disclosed in detail below. Moreover, whilefilter assembly 110 is shown having a relatively tall and narrowconfiguration, it should be understood that other dimensional andgeometrically shaped configurations may be constructed, depending uponthe shape and configuration of the filter element contained therein, theplacement of the various inlet and outlet ports or passages, the spatiallimitations of the apparatus to which the filter assembly is attached,and other factors. The various fittings and connectors, illustrativelybarbed connectors and quick connects (shown in other figures), for thevarious ports and passages of filter assembly 110 are conventional inthe industry and are disclosed as a matter of illustration and notlimitation.

Referring now to FIGS. 2 and 10, in another aspect of the disclosure, aliquid recovery filter is shown designated generally as filter assembly210. It should be understood that the length and width of any of thefilter embodiments shown in the drawings are by way of illustration andnot limitation, and will depend upon the configuration of the filterelement installed therein according to the intended use and operatingenvironment.

Filter assembly 210 includes a housing or shell designated generally as211 having a shell wall 212 with an inlet end 214 and an opposite outletend 216, each secured to, or integral with, shell wall 212. Thecombination of shell wall 212, and ends 214 and 216 define an internalvolume 228. An inlet port 218 extends from inlet end 214 substantiallyaxially parallel to a longitudinal axis of the enclosed filter, asdefined by its inlet and outlet ends. It should be understood that theparallel orientation of inlet port 218 relative to the longitudinal axisof the enclosed filter may be altered (angled away from a parallelorientation including an orthogonal orientation), to accommodateparticular spatial needs. Inlet port 218 is in fluid communication withan upstream internal volume 234 defined by the combination of shell 211and an upstream designated surface of a filter element 230 (moreparticularly an upstream designated surface of the filter element andfiltration material as defined above) secured in the filter assembly.

An outlet port 220 extends coaxially (with the filter) from outlet end216 and is in fluid communication with a core 232, or downstream side offilter element 230. As shown in FIG. 2, outlet port 220 has alongitudinal axis aligned with the longitudinal axis of the enclosedfilter element. It should be understood this orientation can be altered(offset), in similar fashion to inlet port 218 to accommodate specificspatial needs.

A recovery port 222 extends from upper inlet end 214 of filter housing211. Recovery port 222 communicates with the outlet portion or core 232of the filter element disposed within housing 211, as described in moredetail below. Recovery port 222 is shown as being oriented coaxiallywith the enclosed filter element in FIG. 2 and radially in FIG. 10. Itshould be understood that although the lumen of recovery port 222 mustbe in physical communication with core 232, i.e., an extension of thecore space, a recovery filter 223 (disclosed in more detail below) mayblock the flow of liquids from the core into port 222 (but not gas flowfrom the port into the core), the coaxial or radial orientation can bealtered to accommodate spatial needs. Recovery filter 223 is shownconnected in-line (outside of, or within housing 211 as disclosedhereinbelow) to recovery port 222 such that any air, gas, or other fluidintroduced into recovery port 222 must first pass through recoveryfilter 223 prior to contacting the downstream filtered liquid.

Recovery filter 223—as well as all recovery filters throughout thisdisclosure—is chosen to have the appropriate properties, e.g., porosity,pore size, material compatibility with gas or liquids exposed to thefilter, and efficiency rating to ensure that fluids entering the filterassembly through recovery port 222 are of an appropriate purity forcontact with the downstream filtered liquid. In the case of sterilefiltration in the pharmaceutical industry, a sterile filter could beselected as the recovery filter. However, recovery filters with otherefficiency ratings (more or less efficient than a sterile filter) andwith specific purification properties (such as adsorptive capacitiesthrough the use of activated carbon, desiccants, soda-lime, etc. orother depending on the purity requirements of the downstream filteredliquid) could be selected.

As a further alternative, filter materials with hydrophobic propertyfunctions may be used to prevent or reduce the likelihood of therecovery filter being wet by the processing liquid. Of course, it shouldbe understood that there could be applications when a filter materialwith hydrophilic properties and/or combined hydrophilic/hydrophobicproperties may be used as the recovery filter and should be consideredwithin the scope of the disclosure. Preventing the recovery filter frombeing wetted is beneficial, as it allows the recovery filter to moreeasily pass air or gas introduced through recovery port 222. In somecases, the use of oleophobic or super-hydrophobic recovery filters orrecovery filters with other surface properties is beneficial to furtherreduce the likelihood of wetting by the processing fluid. Recoveryfilter 223 may be of any type (e.g. disc, pleated cartridge, etc.) as isknown in the art for filters and can be removable and/or replaceable, orpermanently attached to recovery port 222 in a permanent, reusable orreplaceable housing using any method known for attaching filters as isknown in the art.

An upstream vent port 224 also extends from inlet end 214 to ventupstream internal volume 234. Lastly, an upstream drain port 226 extendsfrom outlet end 216 for draining liquids from upstream internal volume234.

As previously disclosed, filter shell or housing 211 defines internalvolume 228 having a filter element 230 disposed therein. The filterelement may have a generally toroidal configuration and a hollowdownstream core 232. It should be understood that filter element 230 aswell as all filter elements or cartridges disclosed herein (functioningas a processing filter that performs the primary filtering function ofthe filter assembly) may conform to any regular or irregular geometricshape and configuration, e.g., pleated, hollow fiber, tubular, stackeddisc, and may be formed from a variety of materials, e.g., polymeric,ceramic, or metallic membranes, hydrophobic membrane, hydrophilicmembrane, nonwoven media and combinations thereof, with varying poresizes, porosities, surface areas, and the like and still be within thescope and spirit of the disclosed and claimed filter assemblyembodiments. It further should be understood for filter elements madefrom, for example, hollow fiber and tubular materials, there is no“core”, but one or more lumen that collectively function as a core insimilar fashion to the core disclosed herein. It should be also furtherunderstood that filter 230 may be secured in any of the disclosed filterhousings via thermal or sonic bonding, adhesive, O-ring seals and anycombination of these methods as well any other method such as matedthreading used to secure filters in housings as are well known in theart.

As previously disclosed, recovery filter 223 provides a barrier tocontamination entering the downstream portion of filter assembly 210.Recovery filter 223 may be secured in any of the disclosed embodimentsvia permanent methods including thermal or sonic bonding, adhesive, andany combination of these methods as well any other method to securefilters as is well known in the art or via removable non-permanent orsemi-permanent methods such as mated threading, O-ring seals, sanitaryfittings and any combination of these methods as well as any othernon-permanent or semi-permanent method used to secure filters as is wellknown in the art.

As previously disclosed, the combination of shell or housing 211 and anupstream designated surface of filter element 230 define an upstreamvolume 234. For filter elements not having a generally toroidalconfiguration with a downstream core, upstream volume portion 234 isdefined similarly by housing 211 and an upstream designated surface ofthe filter element.

To control the flow of liquids through filter assembly 210, each of thevarious ports 218 through 226 may include a dedicated valve therein.Although each port may be configured with a valve, different embodimentsmay be configured with valves for only some and even none of thepassages and/or ports. Multiple combinations of passages and ports withor without valves are within the contemplation and scope of thedisclosure. As used herein, numeric reference characters designatingvalves will include a “v” at the end of the numerical designation.Dedicated valves for selective ports of filter assembly 210 aredesignated as valves 222 v through 226 v. Valves 222 v, 224 v and 226 vare shown schematically in FIG. 2. All optional dedicated valves may beany suitable type of valve, e.g., needle valves, known and used in theart.

In the embodiment shown in FIGS. 2 and 10, during normal filteringoperations, valves 222 v, 224 v, and 226 v often remain closed. Withthis port and associated valve setting configuration, liquid enters viainlet port 218 and passes into upstream volume 234, through permeablefilter element 230, into hollow core 232 where the liquid is nowfiltered liquid and exits filter assembly 210 through the downstream oroutlet port 220. In the case of filtration processes common in thebiopharmaceutical industry, the filtered liquid is sterile.

The above-described operation should not present any problems withliquid recovery, as long as the filter element is in good working order,the various passages are clear and the operation is essentiallycontinuous. However, when the filtration process is completed, or thefilter must be disconnected from the downstream process for some reason,e.g., because the filter has become plugged, to clean the liquiddelivery lines or passages, to replace the filter or filter element,etc., some quantity of both unfiltered and filtered liquid is typicallytrapped within the filter assembly 210. As this liquid is often quitevaluable, particularly in the pharmaceutical industry, it represents afairly substantial financial cost, or loss, if it is discarded whenfilter assembly 210 is removed or replaced. Furthermore, efforts tocapture the liquid from commercially available filter assemblies orproducts risk breach of asepsis on the downstream/sterile side of thefilter assembly in pharmaceutical applications, or general contaminationin non-sterile applications. Moreover, there may be additional costsassociated with disposing of a filter containing such a liquid,particularly if the liquid is considered to be a biohazard or requiresspecial handling to contain and/or discard.

The various aspects and embodiments of the liquid recovery filterassemblies disclosed herein are configured to address this problem byproviding structural and procedural means to evacuate the filter housingor shell wall, core, and downstream lines of resident liquid in asterile or otherwise contamination-free manner through the designatedfilter outlet port when the filtering operation is terminated. Thispermits the recovery of the valuable liquid within the filter for use,storage, packaging, or further downstream processing.

With respect to filter assembly 210, liquid, filtered and unfiltered,resident in the assembly (and/or lines downstream of the assembly) afterthe desired liquid filtration process has been accomplished, may beremoved from the assembly via a two-step process. At this point in theprocess, valves 222 v, 224 v and 226 v remain in a closed condition, thesame condition in which these valves are commonly maintained during theprimary filtering operation. One or more of these valves may be openedduring start-up of the primary filtering operation to facilitate initialliquid flow through the filter assembly, but are otherwise commonlyclosed during the primary filtering operation. In some applications,some or all of these valves remain opened or partially opened tocontinually remove gas as it builds up in the upstream or downstreamportions, or to monitor pressure in the filter assembly, or for otherpurposes as are well known in the art.

Filtration of the unfiltered liquid remaining within the upstream orinlet side volume portion 234 is accomplished by forcing it through thefilter element 230 as processed or filtered liquid from the filteroutlet passage 220. Positive gas pressure can be used to achieve thisgoal by attaching a compressed air/gas line to the upstream tubing, thefilter inlet port 218, the filter upstream vent port 224, or the filterupstream drain port 226 to drive air/gas into the filter assembly. Ifthe compressed gas is attached to an upstream port other than the inlet,the valve(s) on the port to which the compressed air/gas is attachedmust be opened to allow the compressed air to enter into the upstreamvolume portion 234. In this case, the inlet would need to be closed byway of a valve, tubing clamp, welded tubing, or other means well knownin the art to prevent the compressed air/gas from escaping and to allowpressure to build at the upstream or inlet side of the filter element.

The upstream port may be constructed with a filter of similar design andfunction to a recovery filter to preclude further contamination of theliquid prior to being forced through the filter element by the air orgas introduced through the upstream passage. However, since the liquidwill be filtered by the process filter element 230 prior to reaching thedownstream (clean) side, this is generally unnecessary. If positive gaspressure, a peristaltic pump or other positive displacement pump, or anymeans capable of driving gas into the filter housing is used to bringliquid to the filter, the same means can be used to drive air or gasinto the filter assembly after the liquid source is exhausted. Theupstream ports not used to introduce air or gas into the filterassembly, e.g., valves 222 v, 224 v and 226 v when bringing air or gasinto the system via inlet port 218, will be closed to allow the pressureon upstream volume portion 234 to build up in the filter assembly fromabout 5 to about 10 psi, but higher pressures can be used, if requiredto achieve flow due to a plugged filter element, or a high viscosityliquid so long as maximum pressure limits are not exceeded.

Once the pressure buildup has reached this pressure range and theunfiltered liquid remaining within the upstream side has passed to thedownstream side, the clamp or valve upstream of the port used tointroduce air or gas into the filter assembly, e.g., inlet 218 whenbringing air or gas into the system via the inlet port 218, is engagedto stop all flow into filter assembly 210. It should be understood thatin order to maintain pressure within the desired range, the flow of gasmay be periodically stopped to give liquid time to flow to thedownstream side and then restarted to make-up pressure lost as a resultof liquid (as well as low levels of gas) flowing to the downstream side.Alternatively, if positive gas pressure is used, a regulator can be usedto maintain pressure within the desired range. At this point in theprocess, the downstream side of filter element 230 should be at or aboutambient pressure.

To initiate the second step, valve 222 v is opened. This permits anyliquid remaining in outlet core 232 to flow into outlet port 220 and outof filter assembly 210 via gravity or compressed air/gas assist. The gasmay be, illustratively, air, nitrogen, carbon dioxide, etc., asapplication appropriate. If compressed air is to be used for thispurpose, a compressor or like device is attached, if needed, to recoveryport 222 and regulated to the appropriate pressure. Any air introducedinto recovery port 222 must first pass through recovery filter 223 toensure the filtered liquids forced out of outlet core 232 remain sterileand/or free from contamination. The compressed air/gas should beintroduced into the assembly from about 1 to about 2 psi, or at somepressure lower than the upstream pressure to prevent flow from thedownstream side to the upstream side of filter element 230. The pressureis also chosen to provide the desired liquid recovery rate as well as tomaintain a pressure below the maximum pressure rating or maximumrecommended operating pressure for all components in the system that maybecome pressurized.

During this second step of the liquid recovery process, it should benoted that valves 224 v and 226 v remain closed if pressurizing on theupstream side via inlet port 218. Once this second step is completed,i.e., all, or substantially all, of the liquid resident in outlet core232 has been evacuated, the compressed air/gas source can be turned off,and/or the pressure can be otherwise relieved.

A brief discussion of the characteristics of a conventional filterelement, similar to element 230 is warranted. Filter elements used inmany areas of the pharmaceutical industry, and likewise for otherindustries and operations, often utilize extremely fine filtrationmembranes having pore size ratings on the order of fractional micronsizes. One characteristic of microporous membranes and filtersconstructed of these membranes is known as the “bubble point” of themembrane or filter, i.e., the differential pressure required to forceair (or other gas) through the wetted membrane or filter element. As iswell known in the art, the smaller the filter pore size, the greater thebubble point. The bubble point of many filters used in thepharmaceutical industry may be 40 psi, or even higher, so the pressurerequired to force a gas through the wetted filter membrane can exceedthe maximum pressure rating of componentry often used to producesingle-use systems common in the pharmaceutical industry.

With this explanation in mind, to maximize filtered liquid recovery withrespect to currently available filter assemblies (as well as for any ofthe filter assembly embodiments disclosed herein), air (or other gas)applied to the open upstream vent port 224 or inlet port 218 atsufficient pressure to force the residual unfiltered liquid through thefilter element 230 and out of the upstream volume 234 can efficientlyremove much of the unfiltered liquid within upstream volume 234.However, in order to recover the liquid as filtered and processedliquid, the liquid must further travel through core 232 and outletpassage 220 as well as any lines downstream of the filter assembly. Dueto the properties of a conventional filter element, the gas applied tothe upstream side of filter element 230 cannot travel through themembrane to evacuate core 232 and outlet passage 220 as well as anylines downstream of the filter assembly unless the bubble point pressureis exceeded. This presents a problem, as described previously, due tothe common use of relatively high bubble point filter elements coupledwith the pressure limitations commonly found in systems and filterassemblies themselves.

Although not part of the filtered liquid recovery process for which thisdisclosure is directed, should any unfiltered liquids remain in upstreaminternal volume 234 after pressure is applied to force unfilteredliquids through the filter membrane, drain valve 226 v may be opened topermit the unfiltered liquids to drain via gravity (often once theupstream volume 234 has been depressurized for safety purposes) throughupstream drain port 226. Valve 224 v may also be opened to overcome anyvacuum effect to facilitate liquid flow out of drain port 226.

The filtered liquid remaining in core 232 and outlet passage 220 as wellas any lines downstream of the filter assembly cannot easily berecovered using currently available filter assemblies without risk toasepsis or contamination of the filtered liquid. Due to the use ofrecovery port 222 and recovery filter 223, the pressure of gas needed toevacuate the resident liquid within the downstream portion of the filterassembly will be lower than what would be needed if recovery port 222was not incorporated into the disclosed filter assemblies andcontamination of the filtered liquid being removed from filter core 232by the air or gas introduced through recovery port 222 will beprevented.

The configuration of filter assembly 210 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 210 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that such that outlet port 220, reassigned as an inletport, is located at the gravitational top or high position. Upstreamdrain port 226 (and an optional drain port valve 226 v, if present) isreassigned as a downstream recovery port (and a reassigned optionaldownstream recovery port valve) and will incorporate an inline recoveryfilter similar to, or the same as, recovery filter 223. Recovery port222 (and an optional recovery port valve 222 v, if present) isreassigned as an upstream drain port (and a reassigned optional upstreamdrain port valve) and often maintained in a closed condition during themain filtering operation.

The use of a recovery filter 223 on port 222 is optional in thisfunctional configuration and may require removal in applications wherethe recovery filter's properties (such as its hydrophobicity) wouldprevent port 222 from performing its designated draining function, ifsuch a function is desired. When used in this manner, liquid introducedinto port 220 (with valve 220 v open, if present), flows into core 232(or the lumen of the filter element if constructed from, for example,hollow fiber or tubular material), and radially outwardly through filterelement 230 into internal volume 234 (now a downstream volume) and outof the filter assembly through port 218 as processed liquid. In thisfunctional configuration, the remaining port(s), e.g., port 224 in theembodiment shown in FIG. 2, is/are maintained in a closed condition by,for example, closing inlet valve 224 v in the embodiment shown in FIG.2, or could be eliminated from the embodiment, as use of these portsrisk contamination of the downstream filtered liquid when not coupledwith a recovery filter.

To remove the resident unfiltered liquid (resident in core 232) afterthe primary filtration process, pressurized gas is introduced into thefilter assembly via recovery port 222 (reassigned as an upstream drainport), or through port 220 in a similar fashion by using the reassignedports as disclosed previously for the functional configuration thatflows from volume 234 to core 232. Alternatively, a reassigned upstreamvent port at the reassigned gravitational top 216 (not pictured in FIG.2) could be used to introduce the pressurized gas.

Reassigned recovery port 222 may include an inline recovery filterreassigned as an upstream filter 223 to preclude further contaminationof the liquid prior to being forced through the filter element 230 bythe air or gas introduced through the reassigned upstream vent passage222. However, as previously described, since the liquid will be filteredby the process filter element 230 prior to reaching the reassigneddownstream volume 234 (clean) side, this is generally unnecessary. Also,as previously described, the inclusion of a recovery filter reassignedas an upstream filter 223 may limit the reassigned function of port 222as an upstream drain port, if the recovery filter's properties (such asits hydrophobicity) would prevent liquid from flowing through port 222.Once the resident unfiltered liquid is forced through filter element230, filtered liquid remaining in internal volume 234 may be removed byintroducing pressurized gas into the filter assembly via port 226, toforce the remaining liquid through port 218, in a similar fashion (byusing the reassigned ports) as disclosed previously for the functionalconfiguration which flows from volume 234 to core 232.

Referring now to FIGS. 3 and 8, in another aspect of the disclosure, analternative embodiment of the liquid recovery filter assembly is showndesignated generally as 310. Filter assembly 310 includes all of thecomponents and elements disclosed above for filter assembly 210, i.e., afilter housing or shell 311 having a shell wall 312 with mutuallyopposed first or upper and second or lower ends designated 314 and 316,respectively, (the combination of which define an internal volume 328),and a toroidal filter element 330 secured therein. An upstream surface(or designated upstream surface) of filter element 330 and surroundinghousing 311 define an upstream or inlet volume 334 therebetween. In theembodiment shown, filter element 330 has a hollow core 332, but may alsobe one of the other filter constructions disclosed herein.

An upstream vent port 324 and its optional associated valve 324 v extendfrom upper end 314. An opposite upstream drain port 326 and its optionalassociated valve 326 v extend from lower end 316 as shown schematicallyin FIG. 3, but not in FIG. 8. A downstream recovery port 322 extendsfrom upper end 314 and has an optional recovery port valve 322 v securedinline therein. A recovery filter 323 is secured in line with port 322between upper end 314 and valve 322 v, or may be enclosed in filterhousing 311 and in fluid communication with port 322 as disclosed indetail hereinbelow. Recovery filter 323 should be selected from amongthe same construction material options and the sameproperty/characteristic options disclosed for recovery filter 223.

The difference between filter assembly 210 and filter assembly 310 liesin the orientation of their respective inlet and outlet ports orpassages. It will be seen in FIG. 3 that an upstream or inlet port 318and its optional associated valve 318 v extend radially from upper end314. It should be understood this port (and optional associated valve)may extend also from any point on shell wall 312 upstream of filterelement 330.

A downstream or outlet port 320 and its associated valve 320 v extendfrom filter core 332 radially from lower end 316. It should beunderstood this port (and optional associated valve) may extend alsofrom any point on shell wall 312 downstream of filter element 330. Thisconfiguration may be more readily installed in certain processingsystems than the inline configuration of filter assembly 210. The liquidflow paths through filter assembly 310 during normal filteringoperations and during the draining or recovery of liquids from filterassembly 310 are essentially the same as those disclosed above forfilter assembly 210.

During normal filtering and recovery operations, filter assembly 310 isoperated in the same manner as disclosed for filter assembly 210. Thepositions of the valves present on filter assembly 310 (open, closed,partially open) during normal filtering and recovery operations areidentical to the corresponding valve positions of the correspondingvalves of filter assembly 210 during normal filtering and recoveryoperations, e.g., upstream vent port valve 324 v, and upstream drainport valve 326 v (corresponding to upstream vent port valve 224 v andupstream drain port valve 226 v) are commonly closed during the primaryfiltration function. As such, the disclosure regarding the operation offilter assembly 210 for normal (primary) filtering and recoveryoperations is incorporated here by reference.

The configuration of filter assembly 310 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 310 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 320, reassigned as an inlet port, islocated at the gravitational top or high position. Upstream drain port326 is reassigned as a downstream recovery port and will incorporate aninline recovery filter similar to, or the same as, recovery filter 323.Recovery port 322 is reassigned as an upstream drain port and oftenmaintained in a closed condition during the main filtering operation.The use of a recovery filter 323 on port 322 is optional in thisfunctional configuration and would need to be removed in certain cases,as disclosed above. When used in this manner, liquid introduced intoport 320 (with valve 320 v open, if present), flows into core 332 (orthe lumen of the filter element if constructed from, for example, hollowfiber or tubular material), and radially outwardly through filterelement 330 into internal volume 334 (now a downstream volume) and outof the filter assembly through port 318 as processed liquid. In thisfunctional configuration, the remaining port(s) (port 324 in theembodiment shown in FIG. 3) is/are maintained in a closed condition (by,for example, closing valve 324 v in the embodiment shown in FIG. 3) orcould be eliminated from the embodiment as use of these ports riskcontamination of the downstream filtered liquid when not coupled with arecovery filter. Once the intended volume of liquid is filtered throughassembly 310, valve 320 v is closed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 310 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection. Accordingly, the procedure disclosed for removing filteredand unfiltered liquid from filter assembly 210 when operated in areverse direction is incorporated here by reference with respect tofilter assembly 310.

Referring now to FIGS. 4, 7, 11, 12 and 13, another alternativeembodiment of the liquid recovery filter assembly is shown designatedgenerally as 410. Filter assembly 410 includes all of the components andelements disclosed above for filter assemblies 210 and 310, i.e., afilter housing or shell 411 having a shell wall 412 with mutuallyopposed first or upper and second or lower ends designated 414 and 416,respectively, the combination of which define an internal volume 428. Atoroidal filter element 430 is secured therein. An upstream surface (ordesignated upstream surface) of filter element 430 and surroundinghousing 411 define an upstream volume 434 therebetween. In theembodiment shown, filter element 430 has a hollow core 432, but may alsobe one of the other filter constructions disclosed herein.

An upstream vent port 424 and its optional associated valve 424 v extendfrom upper end 414. An opposite upstream drain port 426 and its optionalassociated valve 426 v extend from lower end 416. A downstream recoveryport 422 extends from upper end 414 and has an optional recovery portvalve 422 v secured inline therein. A recovery filter 423 is secured inline with port 422 between upper end 414 and valve 422 v, or may beenclosed in filter housing 411 and in fluid communication with port 422as disclosed in detail hereinbelow. Recovery filter 423 should beselected from among the same construction material options and the sameproperty/characteristic options disclosed for recovery filter 223.

Filter assembly 410 may be considered a hybrid of filter assemblies 210and 310. An upstream or inlet port 418 and its optional associated valve418 v extend radially from upper end 414 in essentially the sameorientation as the corresponding component 318 of filter assembly 310.It should be understood this port (and optional associated valve) mayextend also from any point on shell wall 412 upstream of filter element430. A downstream or outlet port 420 and its optional associated valve420 v extend coaxially from filter shell wall 412 in the manner ofoutlet port 220 of filter housing 210. It should be understood this portorientation can be altered (offset), in similar fashion as described forinlet port 218 to accommodate specific spatial needs.

During normal filtering and recovery operations, filter assembly 410 isoperated in the same manner as disclosed for filter assemblies 210 and310. The positions of the valves present on filter assembly 410 (open,closed, partially open) during normal filtering and recovery operationsare identical to the corresponding valve positions of the correspondingvalves of filter assembly 210 during normal filtering and recoveryoperations, e.g., upstream vent port valve 424 v, and upstream drainport valve 426 v (corresponding to upstream vent port valve 224 v andupstream drain port valve 226 v) are commonly closed during the primaryfiltration function. As such, the disclosure regarding the operation offilter assembly 210 for normal (primary) filtering and recoveryoperations is incorporated here by reference.

The configuration of filter assembly 410 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 410 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 420, reassigned as an inlet port, islocated at the gravitational top or high position. Upstream drain port426 (and if present, optional drain port valve 426 v) is reassigned as adownstream recovery port (and optional downstream recovery port valve)and will incorporate an inline recovery filter similar to, or the sameas, recovery filter 423. Recovery port 422 (and if present, optionalrecovery port valve 426 v) is reassigned as an upstream drain port (andoptional reassigned upstream drain port valve) and often maintained in aclosed condition during the main filtering operation. The use of arecovery filter 423 on port 422 is optional in this functionalconfiguration and may need to be removed in certain cases, as disclosedabove. When used in this manner, liquid introduced into port 420 (withvalve 420 v open, if present), flows into core 432 (or the lumen of thefilter element if constructed from, for example, hollow fiber or tubularmaterial), and radially outwardly through filter element 430 intointernal volume 434 (now a downstream volume) and out of the filterassembly through port 418 as processed liquid. In this functionalconfiguration, the remaining port(s) (port 424 in the embodiment shownin FIG. 4) is/are maintained in a closed condition (by, for example,closing valve 424 v in the embodiment shown in FIG. 4), or could beeliminated from the embodiment, as use of these ports risk contaminationof the downstream filtered liquid when not coupled with a recoveryfilter.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 410 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection. Accordingly, the procedure disclosed for removing filteredand unfiltered liquid from filter assembly 210 when operated in areverse direction is incorporated here by reference with respect tofilter assembly 410.

Referring now to FIGS. 5 and 9, a liquid recovery filter assembly 510 isshown that includes corresponding components to those disclosed abovefor filter assemblies 210 through 410, i.e., a filter housing or shell511 having a shell wall 512 with mutually opposed first or upper andsecond or lower ends designated 514 and 516, respectively, collectivelydefining an internal volume 528. A toroidal filter element 530 issecured therein. An upstream surface (or upstream designated surface) offilter element 530 and surrounding housing 511 define an upstream orinlet volume 534 therebetween. Filter element 530 has a hollow core 532,but may also be one of the other filter constructions disclosed herein.

An upstream vent port 524 and its optional associated valve 524 v extendfrom upper end 514. An opposite upstream or inlet side drain port 526and its optional associated valve 526 v extend from lower end 516 asshown schematically in FIG. 5, but not in FIG. 9. A downstream recoveryport 522 extends from upper end 514 and has an optional recovery portvalve 522 v secured inline therein. A recovery filter 523 is securedin-line with port 522 between upper end 514 and valve 522 v, or may beenclosed in filter housing 511 and in fluid communication with port 522and filter core 532 as disclosed in detail hereinbelow. Recovery filter523 should be selected from among the same construction material optionsand the same property/characteristic options disclosed for recoveryfilter 223.

The placement of an upstream or inlet port 518 (and an optional inletport valve 518 v secured in-line with the port) extending substantiallyradially from lower end 516 and a downstream or outlet port 520 (and anoptional outlet port valve 520 v secured in-line with the port) alsoextending substantially radially from lower end 516 (albeit from anopposite or different radial direction relative to a filter assemblylongitudinal axis) requires liquid passing through filter assembly 510to flow initially upward into upstream volume 534 through filter element530 then downwardly through core 532 and into outlet port 518 from whichthe filtered liquid exits the filter assembly. This flow path should notpresent any problems with flow, particularly with pressurized filteringsystems. Apart from this flow path distinction, liquid flow throughfilter assembly 510 is substantially as disclosed above for the otherfilter assembly embodiments.

During normal filtering and recovery operations, filter assembly 510 isoperated in the same manner as disclosed for filter assembly 210. Thepositions of the valves present on filter assembly 510 (open, closed,partially open) during normal filtering and recovery operations areidentical to the corresponding valve positions of the correspondingvalves of filter assembly 210 during normal filtering and recoveryoperations, e.g., upstream vent port valve 524 v, and upstream drainport valve 526 v (corresponding to upstream vent port valve 224 v andupstream drain port valve 226 v) are commonly closed during the primaryfiltration function. As such, the disclosure regarding the operation offilter assembly 210 for normal (primary) filtering and recoveryoperations is incorporated here by reference.

The configuration of filter assembly 510 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 510 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration that differs from thereverse functional configurations of filter assembly embodiments 210,310, 410 and 610, the assembly may be maintained in the orientationshown schematically in FIGS. 5 and 9, such that outlet port 520,reassigned as an inlet port, remains located at the gravitational bottomor low position. It should be noted that reorientation is not necessaryfor this functional configuration compared to the orientation shown asthe reassigned outlet port is located at the gravitational bottom or lowposition in the orientation shown schematically in FIGS. 5 and 9.Upstream vent port 524 is reassigned as a downstream recovery port andwill incorporate an inline recovery filter similar to, or the same as,recovery filter 523. Recovery port 522 is reassigned as an upstream ventport and often maintained in a closed condition during the mainfiltering operation.

The use of a recovery filter 523 on port 522 is optional in thisfunctional configuration. When used in this manner, liquid introducedinto port 520 (with valve 520 v open, if present), flows into core 532(or the lumen of the filter element if constructed from, for example,hollow fiber or tubular material), and radially outwardly through filterelement 530 into internal volume 534 (now a downstream volume) and outof the filter assembly through port 518 as processed liquid. In thisfunctional configuration, the remaining port(s) (port 526 in theembodiment shown in FIG. 5) is/are maintained in a closed condition (by,for example, closing valve 526 v in the embodiment shown in FIG. 5) orcould be eliminated from the embodiment, as use of these ports riskcontamination of the downstream filtered liquid when not coupled with arecovery filter. Once the intended volume of liquid is filtered throughassembly 510, valve 520 v may be closed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 510 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection, with the noted exception that in filter assembly 510, port524 is reassigned as a downstream recovery port (providing comparablefunctionality to port 226 reassigned as a downstream recovery port infilter assembly 210) and port 526 is maintained closed, or may beremoved. Accordingly, the procedure disclosed for removing filtered andunfiltered liquid from filter assembly 210 when operated in a reversedirection is incorporated here by reference with respect to filterassembly 510.

Referring now to FIG. 6, a yet further aspect of the liquid recoveryfilter assembly designated generally as 610 has a configuration thatdiffers from that of filter assembly 510, i.e., filter assembly 610'sfilter inlet port extends radially from an upper end of the filterassembly rather than from a lower end as shown for filter assembly 510.Filter assembly 610, however, includes several components correspondingto those disclosed above for filter assemblies 210 through 510, i.e., afilter housing or shell 611 having a shell wall 612 with mutuallyopposed first or upper and second or lower ends 614 and 616,respectively, collectively defining an internal volume 628. A toroidalfilter element 630 is secured therein. Filter element 630 andsurrounding housing 611 define an upstream or inlet volume 634therebetween. Filter element 630 has a hollow core 632.

An upstream vent port 624 and its associated valve 624 v extend radiallyfrom upper or inlet end 614. An opposite upstream or inlet side drainport 626 and its associated valve 626 v extend downwardly from lower end616. A recovery port 622 and its optional associated valve 622 v extendfrom upper end 614 and are in fluid communication with core 632. Arecovery filter 623 is secured in-line and in fluid communication withport 622 between core 632 and recovery port valve 622 v. Recovery filter623 should be selected from among the same construction material optionsand the same property/characteristic options disclosed for recoveryfilter 223.

Liquid flow through filter housing 610 is essentially the same asdisclosed above for filter assembly 310. Liquid flow during normalfiltering operations initially passes through radially disposed inletport 618 and its normally open valve 618 v at upper end 614, and thenenters upstream internal volume 634. The liquid then passes throughfilter element 630 into filter core 632, and downwardly out of core 632to flow out of filter assembly 610 from radially disposed downstream oroutlet port 620 and its normally open valve 620 v at lower end 614.

During normal filtering and recovery operations, filter assembly 610 isoperated in the same manner as disclosed for filter assemblies 210through 510. The positions of the valves present on filter assembly 610(open, closed, partially open) during normal filtering and recoveryoperations are identical to the corresponding valve positions of thecorresponding valves of filter assembly 210 during normal filtering andrecovery operations, e.g., upstream vent port valve 624 v, and upstreamdrain port valve 626 v (corresponding to upstream vent port valve 224 vand upstream drain port valve 226 v) are commonly closed during theprimary filtration function. As such, the disclosure regarding theoperation of filter assembly 210 for normal (primary) filtering andrecovery operations is incorporated here by reference.

The configuration of filter assembly 610 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 610 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 620, reassigned as an inlet port, islocated at the gravitational top or high position. Upstream drain port626 is reassigned as a downstream recovery port and will incorporate aninline recovery filter similar to, or the same as, recovery filter 623.Recovery port 622 is reassigned as an upstream drain port and oftenmaintained in a closed condition during the main filtering operation.

The use of a recovery filter 623 on port 622 is optional in thisfunctional configuration and may need to be removed in certain cases, asdisclosed above. When used in this manner, liquid introduced into port620 (with valve 620 v open, if present), flows into core 632 (or thelumen of the filter element if constructed from, for example, hollowfiber or tubular material), and radially outwardly through filterelement 630 into internal volume 634 (now a downstream volume) and outof the filter assembly through port 618 as processed liquid. In thisfunctional configuration, the remaining port(s) (port 624 in theembodiment shown in FIG. 6) is/are maintained in a closed condition (by,for example, closing valve 624 v in the embodiment shown in FIG. 6), ormay be eliminated from the embodiment, as use of these ports riskcontamination of the downstream filtered liquid when not coupled with arecovery filter. Once the intended volume of liquid is filtered throughassembly 610, valve 620 v is closed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 610 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection. Accordingly, the procedure disclosed for removing filteredand unfiltered liquid from filter assembly 210 when operated in areverse direction is incorporated here by reference with respect tofilter assembly 610.

Referring now to FIG. 21, in another aspect of the disclosure, a liquidrecovery filter is shown designated generally as filter assembly 710.This schematic representation shows an embodiment very similar to 210disclosed in FIGS. 2 and 10; however, additional detail and features areshown to highlight how a replaceable filter cartridge may be disposed ina filter assembly housing or shell that can be disassembled to retrieveand replace used cartridges. Filter assembly 710 is configured as asingle round housing that encloses a single filter cartridge. It shouldbe understood that the length and width and overall geometricconfiguration of the filter assembly embodiment shown in FIG. 21 is byway of illustration and not limitation, and will depend upon theconfiguration of the filter element installed therein according to theintended use and operating environment.

Filter assembly 710 includes a housing or shell 711 having a shell wall712 with an upper end cap 714 and an opposite lower end cap 716, both ofwhich are secured to shell wall 712. It should be understood that eitherend cap can be integral to shell wall 712 as long as one of the end capsis removable to permit extraction and replacement of the enclosed filtercartridge. The combination of shell wall 712, upper end cap 714 andlower end cap 716 define a filter assembly inner chamber 728.

In the configuration shown, the two end caps are secured to shell wall712 with band clamps 715 that secure shell wall flanges 713 to upper endcap flanges 717 and lower end cap flanges 719. It should be understoodthat various other methods of attachment may be used such as bolt andnut assemblies or other types of clamps such as sanitary style clamps. Agasket may or may not be used between the registered surfaces of theshell wall and end cap(s).

An inlet port 718 extends (upwardly based on the filter assemblyorientation shown in FIG. 21) from upper end cap 714 axially parallel toa longitudinal axis of the enclosed filter, as defined by its inlet andoutlet ends. It should be understood that the parallel orientation ofinlet port 718 relative to the longitudinal axis of the enclosed filtermay be altered (angled away from a parallel orientation including anorthogonal orientation), to accommodate particular spatial needs. Inletport 718 may also connect directly to shell wall 712 rather than upperend cap 714. Inlet port 718 is in fluid communication with an upstreaminternal volume 734 defined by the combination of shell wall 712, upperend cap 714, lower end cap 716 and a designated upstream surface of anenclosed filter element disclosed in more detail below.

An outlet port 720 extends coaxially (with the filter) downwardly fromlower end cap 716 and is in liquid communication with a filter core 732,or downstream side of the enclosed filter element. As shown in FIG. 21,outlet port 720 has a longitudinal axis aligned with the longitudinalaxis of the enclosed filter element. It should be understood thisorientation can be altered (offset), in similar fashion to inlet port718 to accommodate specific spatial needs. Alternatively, theorientation of inlet port 718 and outlet port 720 may be arranged toconform to the orientations disclosed in embodiments 210 through 610, orto any orientation known in the art for the arrangement of inlet andoutlet ports for filter assemblies.

A recovery port 722 extends from upper end cap 714. Recovery port 722communicates with the outlet portion or core 732 of the filtercartridge, as described in more detail below. Recovery port 722 is shownas being oriented coaxially with the enclosed filter element. It shouldbe understood that although port 722 must be in fluid communication withthe core of the enclosed filter cartridge, the coaxial orientation canbe altered to accommodate spatial needs.

A recovery filter 723 is secured to port 722 between the two ends of theport and is in fluid communication with a lumen formed by the port.Recovery filter 723 should be selected from among the same constructionmaterial options and the same property/characteristic options disclosedfor recovery filter 223. A recovery port valve 722 v is secured to port722 on a side of recovery filter 723 distal from upper end 714. Valve722 v is maintained in a closed position during normal filteringoperations and is opened to permit the introduction of pressurized gasto recovery filtered liquids resident in the filter core (or to functionas a vent).

An optional upstream vent port 724 also extends from upper end cap 714to vent upstream internal volume 734. Lastly, an optional upstream drainport 726 extends from lower end cap 716 for draining liquids fromupstream internal volume 734. This general external configuration offilter assembly 710 is similar to filter assembly 210.

As previously disclosed, filter housing 711 defines internal volume 728having a filter cartridge 730 disposed therein. The filter cartridge mayhave a generally toroidal configuration (such as the pleated cartridgefilter shown in cross-section) and a hollow outlet core 732. It shouldbe understood that filter cartridge 730 may conform to any of theembodiments disclosed herein and be made from any of the materialsdisclosed herein, or from those generally well known in the art forfilter elements.

To secure a first end of filter cartridge 730 in filter assembly 710,upper end cap 714 is formed with an upper cartridge receiving wall 738dimensioned and shaped to conform to the shape of the cartridgeregistration or mounting surfaces of filter cartridge 730 as are wellknown in the art. For cylindrical cartridges, receiving wall 738 iscircular in cross-section (although other cross-sectional shapes arepossible and within the scope of this disclosure), and has an innerdiameter greater than the diameter of the mounting surfaces of filtercartridge 730. Alternatively, receiving wall 738 can be substituted witha mounting post with an outside diameter less than an inner diameter ofan annular axially projecting mounting surface on the cartridge.

With either mounting configuration, to secure filter cartridge 730 toupper end cap 714, one or more O-rings 727 are positioned between thecapsule and filter registration surfaces as shown in FIG. 21 to create areleasable, but substantially liquid tight seal between wall 738 andfilter cartridge 730. As previously stated, it should also be understoodthat the relative diameters of the receiving wall or post 738 and thecartridge mounting surfaces can be reversed wherein the inner diameterof the mounting surfaces are greater than the out diameter of thereceiving wall or post. In this reversed configuration, the O-rings sealthe inner mounting surface of the filter cartridge to the outer surfaceof the receiving wall or post. It should also be understood that othermounting methods, e.g., gasket seals, threading one cartridge end andusing an O-ring seal on the other, or an O-ring seal on one end and aflat gasket seal on the other end, as well as other methods commonlyknown in the art for attaching filter elements into housings may be usedto secure the filter cartridge to the shell wall.

To secure a second end of filter cartridge 730 in filter assembly 710,lower end cap 716 is formed with a lower cartridge receiving wall 736dimensioned and shaped to conform to the shape of the cartridgeregistration surfaces of filter cartridge 730 as are well known in theart. For cylindrical cartridges, lower receiving wall 736 is circular incross-section (although other cross-sectional shapes are possible andwithin the scope of this disclosure) and has an inner diameter greaterthan the diameter of the mounting surfaces of filter cartridge 730. Tosecure filter cartridge 730 to lower end cap 716, one or more O-rings727 are positioned between the surfaces as shown in FIG. 21 to create areleasable, but substantially liquid and air tight seal between wall 736and filter cartridge 730. It should also be understood that the relativediameters of the receiving wall or post 736 and the cartridge mountingsurfaces can be reversed wherein the inner diameter of the mountingsurfaces are greater than the outer diameter of the receiving wall orpost. In this reversed configuration, the O-rings seal the innermounting surface of the filter cartridge to the outer surface of thereceiving wall or post. It should be understood that other mountingmethods, as described elsewhere in the disclosure as well as othermethods commonly known in the art for attaching filter elements intohousings, may be used to secure the filter cartridge to the shell wall.It further should be understood that the filter cartridge can bepermanently secured to one of the end caps and that such end cap can beremoved from housing 711.

In practice, for the embodiment shown in FIG. 21, upper end cap 714 willbe removed from filter assembly 710 and filter cartridge 730 will beplaced into internal volume 728 and inserted into lower receiving wall736. Upper end cap 714 will then be placed onto shell wall 712 withupper receiving wall 738 aligned with a top end of filter cartridge 730.Once upper end cap 714 is fully registered against shell wall 712, clamp715, (or any other method used to secure the end caps), is secured tothe shell wall and end cap flanges to complete the assembly (orre-assembly) process to prepare filter assembly 710 for use, or furtherassembly to a larger assembly. It should be understood that othermethods disclosed herein as well as other methods known in the art forsecuring end caps to housing walls may be used and are within thecontemplation and scope of the disclosure. It further should beunderstood this process may also be reversed whereby the lower cap isremoved and the filter cartridge is inserted into the filter housing andsecured to the upper receiving wall or post first and then secured tothe receiving wall or post of the outlet end cap when the outlet end capis placed back on the filter housing or shell wall.

It should be understood further that the foregoing assembly procedurerelates to filter cartridges designed to be removed and replaced. Forassemblies designed for one-time or continual use, it should be alsofurther understood that filter cartridge 730 may be secured in any ofthe disclosed filter housings via thermal or sonic bonding, adhesive,O-ring seals and any combination of these methods as well as any anotherother method used to secure filters in housings or capsules as disclosedherein and/or well known in the art.

As previously disclosed, the combination of filter housing 711 and anupstream designated surface of filter element 730 define an upstreamvolume 734. Unfiltered liquid enters upstream volume 734 of filterassembly 710 via upstream or inlet passage 718 and passes through liquidpermeable filter element 730 to hollow outlet core 732 of filtercartridge 730, and then exits filter assembly 710 through outlet port720 as filtered liquid.

To control the flow of liquids through filter assembly 710, each of thevarious passages or ports 718 through 726 may include a dedicated valvetherein. Although each passage or port may be configured with a valve,different embodiments may be configured with valves for only some andeven none of the passages and/or ports. Multiple combinations ofpassages and ports with or without valves are within the contemplationand scope of the disclosure. For purposes of illustration as well as forcompleteness of the disclosure, dedicated valves for selective ports offilter assembly 710 are designated as valves 722 v through 726 v. Valves722 v through 726 v are shown schematically in FIG. 21, and may be anysuitable type of valve known in the art.

In the embodiment shown in FIG. 21, during normal filtering and recoveryoperations, filter assembly 710 is operated in the same manner asdisclosed for filter assemblies 210 through 610. The positions of thevalves present on filter assembly 710 (open, closed, partially open)during normal filtering and recovery operations are identical to thecorresponding valve positions of the corresponding valves of filterassembly 210 during normal filtering and recovery operations, e.g.,upstream vent port valve 724 v, and upstream drain port valve 726 v(corresponding to upstream vent port valve 224 v and upstream drain portvalve 226 v) are commonly closed during the primary filtration function.As such, the disclosure regarding the operation of filter assembly 210for normal (primary) filtering and recovery operations is incorporatedhere by reference.

The configuration of filter assembly 710 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 710 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 720, reassigned as an inlet port, islocated at the gravitational top or high position. Upstream drain port726 (and if present, optional drain port valve 726 v) is reassigned as adownstream recovery port (and optional downstream recovery port valve)and will incorporate an inline recovery filter similar to, or the sameas, recovery filter 723. Recovery port 722 (and if present, optionalrecovery port valve 726 v) is reassigned as an upstream drain port (andoptional reassigned upstream drain port valve) and often maintained in aclosed condition during the main filtering operation.

The use of a recovery filter 723 on port 722 is optional in thisfunctional configuration and may need to be removed in certain cases, asdisclosed above. When used in this manner, liquid introduced into port720 (with valve 720 v open, if present), flows into core 732 (or thelumen of the filter element if constructed from, for example, hollowfiber or tubular material), and radially outwardly through filterelement 730 into internal volume 734 (now a downstream volume) and outof the filter assembly through port 718 as processed liquid. In thisfunctional configuration, the remaining port(s) (port 724 in theembodiment shown in FIG. 21) is/are maintained in a closed condition(by, for example, closing valve 724 v in the embodiment shown in FIG.21), or could be eliminated from the embodiment, as use of these portsrisk contamination of the downstream filtered liquid when not coupledwith a recovery filter.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 710 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection. Accordingly, the procedure disclosed for removing filteredand unfiltered liquid from filter assembly 210 when operated in areverse direction is incorporated here by reference with respect tofilter assembly 710.

Referring now to FIG. 22, in another aspect of the disclosure, a liquidrecovery filter is shown designated generally as filter assembly 810.This embodiment is similar to the embodiment shown in FIG. 21 in that itincorporates replaceable filter cartridges disposed in a filter assemblyhousing or shell wall that can be disassembled to retrieve and replaceused cartridges. Filter assembly 810 is configured as a multi-roundhousing that encloses two or more filter cartridges. It should beunderstood that the length and width of the filter assembly embodimentshown in FIG. 22 is by way of illustration and not limitation, and willdepend upon the configuration of the filter elements installed thereinaccording to the intended use and operating environment.

Filter assembly 810 includes a housing or shell 811 having a shell wall812 with an upper inlet end cap 814 and an opposite lower outlet end cap816, both of which are secured to shell wall 812 and that collectivelydefine an internal volume 828. It should be understood that either endcap can be integral to shell wall 812 as long as one of the end caps isremovable to permit extraction and replacement of the enclosed filtercartridges. In the configuration shown, the two end caps are secured toshell wall 812 with band clamps 815 that secure shell wall flanges 813to upper end cap flanges 817 and lower end cap flanges 819. It should beunderstood that various other methods of attachment may be used such asbolt and nut assemblies, or other types of clamps such as sanitary typeclamps. A gasket may or may not be used between the registered surfacesof the shell wall and end caps.

An inlet port 818 extends laterally from shell wall 812. It should beunderstood that the location of inlet port 818 in terms of its height orradial position as well as its orientation relative to the longitudinalaxis of the enclosed filter may be altered (raised, lowered, rotated,angled away from an orthogonal orientation, etc.), to accommodateparticular spatial needs. Inlet port 818 may also may also connectdirectly to inlet cap 814 rather than shell wall 812. Inlet port 818 isin liquid communication with an upstream internal volume 834 defined bythe combination of housing 811 and an upstream designated surface offilter element 830.

An outlet port 820 extends substantially parallel to the longitudinalaxes of enclosed filter cartridges 830 downwardly from lower end cap 816and is in liquid communication with filter cores 832, or downstream sideof the enclosed filter cartridges via an outlet manifold 850 thatconnects cores 832 with outlet 820. As shown in FIG. 22, outlet port 820has a longitudinal axis substantially parallel with the longitudinalaxis of the enclosed filter cartridges. It should be understood thisorientation can be altered (offset), in similar fashion to inlet port818 to accommodate specific spatial needs. Alternatively, theorientation of inlet port 818 and outlet port 820 may conform to theorientations disclosed in embodiments 210 through 610, or to anyorientation known in the art for the arrangement of inlet and outletports for filter assemblies.

As shown in FIG. 22, outlet manifold 850 is formed by a combination of abottom end 851 of shell wall 812 that has portions defining lower endfilter cartridge receiving walls 852 disclosed in more detail below. Itshould be understood that outlet manifold 850 may be formed entirely asan integral part of outlet end cap 816, or an integral part of shellwall 812.

A recovery port 822 extends from upper end cap 814. Recovery port 822communicates with the outlet portions or cores 832 of the filtercartridges via an outlet vent manifold 840, as described in more detailbelow. Recovery port 822 is shown as being oriented substantiallyparallel with the longitudinal axes of the enclosed filter cartridges.It should be understood that although port 822 must be in liquidcommunication with the cores of the enclosed filter cartridges, thesubstantially parallel orientation can be altered to accommodate spatialneeds.

A recovery filter 823 is secured to port 822 between the two ends of theport and is in fluid communication with a lumen formed by the port.Recovery filter 823 should be selected from among the same constructionmaterial options and the same property/characteristic options disclosedfor recovery filter 223. A recovery port valve 822 v is secured to port822 on a side of recovery filter 823 distal from upper end 814. Valve822 v is maintained in a closed position during normal filteringoperations and is opened to permit the introduction of pressurized gasto recovery filtered liquids resident in the filter core (or to functionas a vent).

An upstream vent port 824 also extends from inlet end cap 814 to ventupstream internal volume 834 (defined by the combination of housing 811and upstream designated surfaces of the filter cartridges). Lastly, anupstream drain port 826 extends laterally from a lower end of shell wall812 for draining liquids from upstream internal volume 834 and may belocated at any radial orientation relative to the location of inlet 818.This general external configuration of filter assembly 810 is similar tofilter assembly 110 of FIG. 1, with the exception of the orientation ofinlet port 818 and upstream drain passage 826.

As previously disclosed, filter housing 811 defines an internal volume828 having two or more filter cartridges 830 disposed therein in whatcan be a circular arrangement of filter cartridges although otherorientations (linear, rows, etc.) may be used. The filter cartridges mayhave a generally toroidal configuration (such as the pleated cartridgefilters as shown in cross-section) and hollow outlet cores 832. Itshould be understood that filter cartridges 830 may conform to any ofthe embodiments disclosed herein and be made from any of the materialsdisclosed herein, or from those generally well known in the art forfilter elements.

To secure a first end of filter cartridges 830 in filter assembly 810,vent manifold 840, secured to inlet end cap 814, is formed with aplurality of upper cartridge receiving walls 842 dimensioned and shapedto conform to the shape of the cartridge registration or mountingsurfaces of filter cartridges 830 as are well known in the art. Forcylindrical cartridges, receiving walls 842 will be circular incross-section (although other cross-sectional shapes are possible andwithin the scope of this disclosure) and have an inner diameter greaterthan the diameter of the mounting surfaces of filter cartridges 830.

To secure filter cartridge 830 to inlet cap 814, one or more O-rings 827are positioned between the surfaces as shown in FIG. 22 to create areleasable, but substantially liquid and air tight seal between walls838 and filter cartridges 830. It should also be understood that therelative diameters of the receiving walls or posts 838 and thecartridges' mounting surfaces can be reversed wherein the inner diameterof the mounting surfaces are greater than the out diameter of thereceiving walls or posts. In this reversed configuration, the O-ringsseal the inner mounting surfaces of the filter cartridges to the outersurfaces of the receiving wall or post. It should also be understoodthat other mounting methods, e.g., flat gasket seals, threading onecartridge end and using an O-ring seal on the other, or an O-ring sealon one end and a flat gasket seal on the other end, as well as othermethods commonly known in the art for attaching filter elements intohousings (as well as any of the methods disclosed for filter assembly710), may be used to secure the filter cartridges to the shell walls.

To secure second ends of filter cartridges 830 in filter assembly 810,the bottom end of shell wall 812, (or portions of outlet end cap 816),is formed with a plurality of lower cartridge receiving walls 852dimensioned and shaped to conform to the shape of the cartridgeregistration surfaces of filter cartridges 830 as are well known in theart. For cylindrical cartridges, lower receiving walls 836 will becircular in cross-section (although other cross-sectional shapes arepossible and within the scope of this disclosure) and have innerdiameters greater than the diameters of the mounting surfaces of filtercartridges 830. To secure filter cartridges 830 to outlet cap 816, (orbottom end of shell wall 812), one or more O-rings 827 are positionedbetween the surfaces as shown in FIG. 22 to create a releasable, butsubstantially liquid and air tight seal between walls 852 and filtercartridges 830.

It should be understood that the relative diameters of the receivingwalls or posts 836 and the cartridges' mounting surfaces can be reversedwherein the inner diameter of the mounting surfaces are greater than theout diameter of the receiving walls or posts. In this reversedconfiguration, the O-rings seal the inner mounting surfaces of thefilter cartridges to the outer surfaces of the receiving walls or posts.It also should be understood that other mounting methods, describedelsewhere in this disclosure as well as other methods commonly known inthe art for attaching filter elements to and into housings, may be usedto secure the filter cartridge to the shell wall.

In practice, for the embodiment shown in FIG. 22, inlet cap 814 will beremoved from filter assembly 810 and filter cartridges 830 will beplaced into internal volume 828 and each inserted into one of the lowerreceiving walls 836. Inlet cap 814 will then be placed onto shell wall812 with upper receiving walls 842 each aligned with a top end of one ofthe plurality of filter cartridges 830. Once upper end cap 814 is fullyregistered against shell wall 812, clamps 815, (or any other method usedto secure the end caps), is secured to the shell wall and end capflanges to complete the assembly (or re-assembly) process to preparefilter assembly 810 for use, or further assembly to a larger assembly.It should be understood this process may also be reversed whereby theoutlet cap is removed and the filter cartridges are inserted into thefilter housing and secured to the upper receiving walls or posts firstand then secured to the receiving walls or posts of the outlet end capwhen the outlet end cap is placed back on the filter housing or shellwall.

It should be understood the foregoing assembly procedure relates tofilter cartridges designed to be removed and replaced. For assembliesdesigned for one-time or continual use, it should be also furtherunderstood that filter cartridges 830 may be secured in any of thedisclosed filter housings via thermal or sonic bonding, adhesive, O-ringseals and any combination of these methods as well any another othermethod used to secure filters in housings or capsules as disclosedherein and/or well known in the art.

As previously disclosed, the combination of housing 811 and an upstreamdesignated surface of filter cartridges 830 define an upstream volume834. Unfiltered liquid enters upstream volume 834 via inlet port 818 andpasses through liquid permeable filter cartridges 830 to hollow outletcores 832 of filter cartridges 830, and then exits filter assembly 810through outlet manifold 850 and then outlet port 820 as filtered liquid.

To control the flow of liquids through filter assembly 810, each of thevarious ports 818 through 826 may include a dedicated valve therein.Although each port may be configured with a valve, different embodimentsmay be configured with valves for only some and even none of the ports.Multiple combinations of ports with or without valves are within thecontemplation and scope of the disclosure. For purposes of illustrationas well as for completeness of the disclosure, dedicated valves forselective ports of filter assembly 810 are designated as valves 822 vthrough 826 v. Valves 822 v through 826 v are shown schematically inFIG. 22, and may be any suitable type of valve known in the art.

In the embodiment shown in FIG. 22, during normal filtering and recoveryoperations, filter assembly 810 is operated in the same manner asdisclosed for filter assemblies 210 through 710. The positions of thevalves present on filter assembly 810 (open, closed, partially open)during normal filtering and recovery operations are identical to thecorresponding valve positions of the corresponding valves of filterassembly 210 during normal filtering and recovery operations, e.g.,upstream vent port valve 824 v, and upstream drain port valve 826 v(corresponding to upstream vent port valve 224 v and upstream drain portvalve 226 v) are commonly closed during the primary filtration function.As such, the disclosure regarding the operation of filter assembly 210for normal (primary) filtering and recovery operations is incorporatedhere by reference.

The configuration of filter assembly 810 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 810 in the reverse flow direction, the filter assembly may haveto be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 820, reassigned as an inlet port, islocated at the gravitational top or high position. Upstream drain port826 (and if present, optional drain port valve 826 v) is reassigned as adownstream recovery port (and optional downstream recovery port valve)and will incorporate an inline recovery filter similar to, or the sameas, recovery filter 823. Recovery port 822 (and if present, optionalrecovery port valve 826 v) is reassigned as an upstream drain port (andoptional reassigned upstream drain port valve) and often maintained in aclosed condition during the main filtering operation.

The use of a recovery filter 823 on port 822 is optional in thisfunctional configuration and may need to be removed in certain cases, asdisclosed above. When used in this manner, liquid introduced into port820 (with valve 820 v open, if present), flows into core 832 (or thelumen of the filter element if constructed from, for example, hollowfiber or tubular material), and radially outwardly through filterelement 830 into internal volume 834 (now a downstream volume) and outof the filter assembly through port 818 as processed liquid. In thisfunctional configuration, the remaining port(s) (port 824 in theembodiment shown in FIG. 22) is/are maintained in a closed condition(by, for example, closing valve 824 v in the embodiment shown in FIG.22), or could be eliminated from the embodiment, as use of these portsrisk contamination of the downstream filtered liquid when not coupledwith a recovery filter.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 810 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection. Accordingly, the procedure disclosed for removing filteredand unfiltered liquid from filter assembly 210 when operated in areverse direction is incorporated here by reference with respect tofilter assembly 810.

Referring now to FIG. 14, in another aspect of the disclosure, a liquidrecovery filter is shown designated generally as filter assembly 1010.This embodiment differs from the previously disclosed embodiments inthat it incorporates an aspiration tube 1060 in place of a recovery portor passage. The filter assembly shown in FIG. 14 has a filter elementsecured in a capsule or housing. It should be understood that anaspiration tube can be used in place of a downstream recovery port witha filter configuration incorporating a filter cartridge, such as thoseshown in FIGS. 21 and 22. Filter assembly 1010 is configured as a singleround housing that encloses a single filter element 1030. It should beunderstood further that the length and width of the filter assemblyembodiment shown in FIG. 14 is by way of illustration and notlimitation, and will depend upon the configuration of the filter elementinstalled therein according to the intended use and operatingenvironment.

Filter assembly 1010 includes a housing or shell 1011 having a shellwall 1012 with an upper end 1014 and an opposite lower end 1016. Itshould be understood that either end can be integral to shell wall 1012,or modular in construction as end caps, particularly if a replaceablefilter cartridge is secured in the housing or shell wall to permitextraction and replacement of the enclosed filter cartridge. It shouldalso be understood that upper end 1014 is referenced as upper and lowerend 1016 is referenced as lower as much function is gained from usingthis embodiment in this orientation for liquid recovery; however duringnormal filtration and other times during use it may be possible and evenadvantageous for end 1016 to be oriented gravitationally above end 1014.The means and/or methods used to secure such end caps is the same asdisclosed for the end caps described for filter assemblies 210 through810.

An inlet port 1018 extends laterally from shell wall 1012 or from lowerend 1016. It should be understood that the orientation of inlet port1018 relative to the longitudinal axis of the enclosed filter may bealtered (angled away from its orthogonal orientation), to accommodateparticular spatial needs. Inlet port 1018 is in liquid communicationwith an internal upstream volume 1034 defined by the combination ofshell 1011 and an upstream designated surface of filter element 1030.

An outlet port 1020 also extends laterally from shell wall 1012 or fromlower end 1016 and is in liquid communication with a filter core 1032,or downstream side of the enclosed filter element. As shown in FIG. 14,outlet port 1020 has a longitudinal axis orthogonal to the longitudinalaxis of the enclosed filter element. It should be understood thisorientation can be altered (offset), in similar fashion to inlet port1018 to accommodate specific spatial needs. Furthermore andalternatively, the orientation of inlet port 1018 and outlet port 1020may be configured to the orientations disclosed in embodiments 210through 610 or to any orientation known in the art for the arrangementof inlet and outlet ports for filter assemblies.

Outlet aspiration tube 1060 extends into a lower end of core 1032 fromlower end 1016 and is in fluid communication with downstream recoveryport 1022, core 1032, and the exterior of filter assembly 1010 throughrecovery port 1022. It should be understood that aspiration tube 1060can extend any distance into core 1032 including the distance shown inFIG. 14 and have openings formed anywhere along its length to direct airor gas into the downstream side of element 1030 so as to facilitate andallow downstream liquids to be recovered. Recovery port 1022 extendsoutwardly from end 1016 and is in fluid communication with the outletportion or core 1032 of the filter element via tube 1060, as describedin more detail below. Recovery port 1022 is shown as being orientedcoaxially with the enclosed filter element. It should be understood thatalthough recovery port 1022 must be in fluid communication with the coreof the enclosed filter element, the coaxial orientation can be alteredto accommodate spatial needs.

A recovery filter 1023 is secured to recovery port 1022 between the twoends of the port and is in fluid communication with a lumen formed bythe port. Recovery filter 1023 should be selected from among the sameconstruction material options and the same property/characteristicoptions disclosed for recovery filter 223. A recovery port valve 1022 vis secured to port 1022 on a side of recovery filter 1023 distal fromlower end 1016. Valve 1022 v is maintained in a closed position duringnormal filtering operations and is opened to permit the introduction ofpressurized gas to recover filtered liquids resident in the filter core(or to function as a vent).

An upstream vent port 1024 extends from upper end 1014 to vent upstreaminternal volume 1034 and can be also used to perform other functionsincluding, but not limited to integrity testing and pressurizationduring liquid recovery. Lastly, an optional upstream drain port (notshown) may be included and extend from lower end 1016 for drainingliquids from upstream internal volume 1034. This general externalconfiguration of filter assembly 1010 is similar to filter assembly 510of FIG. 5, with the exception of the absence of an upstream drain portand the location of port 1022 compared with the location port 522, whichis reoriented to lower end 1016 due to the use of tube 1060.

As previously disclosed, filter shell 1011 defines internal volume 1028having a filter element 1030 disposed therein. The filter element mayhave a generally toroidal configuration (such as the pleated filtershown in cross-section) and a hollow outlet core 1032. It should beunderstood that filter element 1030 may conform to any of theembodiments disclosed herein and be made from any of the materialsdisclosed herein, or any materials known in the art for filter elements.Filter element 1030 may be secured in any of the disclosed filterhousings via thermal or sonic bonding, adhesive, O-ring seals and anycombination of these methods as well as any another other method used tosecure filters in housings or capsules as disclosed herein and/or aswell known in the art. For filter elements in the form of filtercartridges, the cartridges may be secured in the housing in the samemanner and with the same features as disclosed and shown in FIGS. 21 and22.

As previously disclosed, the combination of shell 1011 and a designatedupstream surface of filter element 1030 define an upstream volume 1034.Unfiltered liquid enters upstream volume 1034 of filter assembly 1010via inlet port 1018 and passes through filter element 1030 to hollowoutlet core 1032, and then exits filter assembly 1010 through outletport 1020 as filtered liquid.

To control the flow of liquids through filter assembly 1010, each of thevarious ports or tubes 1018 through 1024 (and upstream drain ports insome embodiments) may include a dedicated valve therein. Although eachtube or port may be configured with a valve, different embodiments maybe configured with valves for only some and even none of the tubesand/or ports. Multiple combinations of tubes and ports with or withoutvalves are within the contemplation and scope of the disclosure. Forpurposes of illustration as well as for completeness of the disclosure,dedicated valves for selective ports of filter assembly 1010 aredesignated as valves 1022 v through 1024 v. Valves 1022 v through 1024 vare shown schematically in FIG. 14, and may be any suitable type ofvalve known in the art.

Tube 1060 and downstream recovery port 1022 may be made from aluminum,stainless steel, metallic alloys, or other metal-based materials. Othersuitable materials include polymeric materials including, but notlimited to, polypropylene, nylon, polyester, polyethylene, PSA andcombinations thereof that are generally compatible with the fluidsand/or gasses intended to be introduced into the filter assembly as isknown in the art.

In the embodiment shown in FIG. 14, during normal filtering and recoveryoperations, filter assembly 1010 is operated in the same manner asdisclosed for filter assemblies 210 through 810. The positions of thevalves present on filter assembly 1010 (open, closed, partially open)during normal filtering and recovery operations are identical to thecorresponding valve positions of the corresponding valves of filterassembly 210 during normal filtering and recovery operations, e.g.,upstream vent port valve 1024 v, and upstream drain port valve 1026 v,if present, (corresponding to upstream vent port valve 224 v andupstream drain port valve 226 v) are commonly closed during the primaryfiltration function. As such, the disclosure regarding the operation offilter assembly 210 for normal (primary) filtering and recoveryoperations is incorporated here by reference.

The configuration of filter assembly 1010 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 1010 in the reverse flow direction, the filter assembly mayhave to be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, similar to the reversefunctional configuration disclosed for embodiment 510, the assembly maybe maintained in the orientation shown schematically in FIG. 14, suchthat outlet port 1020, reassigned as an inlet port, remains located atthe gravitational bottom or low position. It should be noted thatreorientation is not necessary for this functional configurationcompared to the orientation shown as the reassigned outlet port islocated at the gravitational bottom or low position in the orientationshown schematically in FIG. 14. Upstream vent port 1024 is reassigned asa downstream recovery port and will incorporate an inline recoveryfilter similar to, or the same as, recovery filter 1023. Recovery port1022 is reassigned as an upstream vent port and often maintained in aclosed condition during the main filtering operation. It should beunderstood, that outlet aspiration tube 1060, as shown in FIG. 14 anddescribed as extending into a lower end of core 1032, would provideimproved venting efficiency if it were to extend upwardly toward, and inclose proximity to, a top end of core 1032, similar to aspiration tube1260 shown in FIG. 17 and disclosed in further detail below.

The use of a recovery filter 1023 on port 1022 is optional in thisfunctional configuration. When used in this manner, liquid introducedinto port 1020 (with valve 1020 v open, if present), flows into core1032 (or the lumen of the filter element if constructed from, forexample, hollow fiber or tubular material), and radially outwardlythrough filter element 1030 into internal volume 1034 (now a downstreamvolume) and out of the filter assembly through port 1018 as processedliquid. In this functional configuration, any the remaining port(s), ifpresent, is/are maintained in a closed condition (by, for example,closing their associated valve) or could be eliminated from theembodiment, as shown in FIG. 14, as use of additional downstream portsrisk contamination of the downstream filtered liquid when not coupledwith a recovery filter. Once the intended volume of liquid is filteredthrough assembly 1010, valve 1020 v may be closed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 1010 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection, with the noted exception that in filter assembly 1010, port1024 is reassigned as a downstream recovery port (providing comparablefunctionality to port 226 reassigned as a downstream recovery port infilter assembly 210) and port 1026 is not depicted. Accordingly, theprocedure disclosed for removing filtered and unfiltered liquid fromfilter assembly 210 when operated in a reverse direction is incorporatedhere by reference with respect to filter assembly 1010.

Referring now to FIG. 17, in an embodiment substantially similar to theone shown in FIG. 14, a filter assembly designated generally as 1210incorporates the same features as filter assembly 1010 except theaspiration tube designated 1260 in filter assembly 1210 extends from itspoint of entry at a bottom end of a filter shell wall 1212 into a filtercore 1232 and extends upwardly toward, and in close proximity to, a topend of a filter element 1230. This aspiration tube places the point ofgas introduction at a higher point in filter core 1232 than itscounterpart, aspiration tube 1060 in filter assembly 1010. Thisconfiguration may improve the efficiency of liquid flow out of filterassembly by more advantageously introducing gas into the filter assemblyat a location less likely to interfere with the flow of liquid outthrough core 1232 and outlet 1220.

The function and operation of filter assembly 1210 is essentially thesame as described and disclosed for filter assembly 1010. Thedescription of the construction of filter assembly 1010 also correspondsto the construction of filter assembly 1210. The disclosure of theconstruction, operation and function of filter assembly 1010 is thusincorporated here to describe the construction, operation and functionof filter assembly 1210. It should be noted that the reference characterdesignations for filter assembly 1010 correspond to, and may betransferred to, filter assembly 1210 by removing the second digit “0” ofeach reference character and replacing it with a “2”.

Referring now to FIG. 15, in a yet further aspect of the disclosure, amulti-round filter assembly incorporating dedicated aspiration tubes andrecovery filters for each enclosed filter element/cartridge is showndesignated generally as 1110. This embodiment differs from thepreviously disclosed single-round filter housing embodiment shown inFIG. 14 in that it incorporates multiple filter elements/cartridges,each with dedicated aspiration tubes 1160 and recovery filters 1123.Each aspiration tube has a dedicated recovery port 1122 and an optionalassociated valve 1122 v. The filter assembly shown in FIG. 15 has afilter element secured in a capsule or housing. It should be understoodthat dedicated aspiration tubes can be used in place of downstreamrecovery ports with a filter configuration incorporating filtercartridges, such as those shown in FIGS. 21 and 22. It should beunderstood further that the length and width of the filter assemblyembodiment shown in FIG. 15 is by way of illustration and notlimitation, and will depend upon the configuration of the filter elementinstalled therein according to the intended use and operatingenvironment.

Filter assembly 1110 includes a housing or shell 1111 having a shellwall 1112 having an upper end 1114 and an opposite lower end 1116. Itshould be understood that either end can be integral to shell wall 1112,or modular in construction as end caps, particularly if a replaceablefilter cartridge is secured in the housing or shell wall to permitextraction and replacement of the enclosed filter cartridge. The meansand/or methods used to secure such end caps are the same as thosedisclosed for the end caps described for filter assemblies 710 and 810.

An inlet port 1118 extends laterally or radially from shell wall 1112.It should be understood that the orientation of inlet port 1118 relativeto the longitudinal axis of the enclosed filter may be altered (angledaway from its orthogonal orientation), to accommodate particular spatialneeds. Inlet port 1118 is in liquid communication with an internalupstream volume 1134 defined by the combination of shell 1111 and anupstream designated surface of filter element 1030.

An outlet port 1120 also extends laterally from shell wall 1112 or fromlower end 1116 and is in liquid communication with filter core 1132, orthe downstream side of the enclosed filter elements. As shown in FIG.15, outlet port 1120 has a longitudinal axis orthogonal to thelongitudinal axis of the enclosed filter element. It should beunderstood that this orientation can be altered (offset), in similarfashion to inlet port 1118 to accommodate specific spatial needs.

Outlet aspiration tubes 1160 each extend into a lower end of one filtercore 1132 from lower end 1116 and are in fluid communication withdownstream recovery ports 1122, cores 1132, and the exterior of filterassembly 1110 through recovery ports 1122. It should be understood, thataspiration tube 1160 can extend any distance into core 1132 includingthe distance shown in FIG. 15 and have openings formed anywhere alongits length to direct air or gas into the downstream side of element 1130so as to facilitate and allow downstream liquids to be recovered.Recovery ports 1122 extend outwardly from end 1116. Each downstreamrecovery port 1122, communicates with the outlet portion or core 1132 ofone filter element 1130 via tube 1160, as described in more detailbelow. Each recovery port 1122 is shown as being oriented coaxially withits corresponding enclosed filter element/cartridge 1130. It should beunderstood that although recovery port 1122 must be in fluidcommunication with the core of the enclosed filter element, the coaxialorientation can be altered to accommodate spatial needs.

A recovery filter 1123 is secured to recovery port 1122 between the twoends of the port and is in fluid communication with a lumen formed bythe port. Recovery filter 1123 should be selected from among the sameconstruction material options and the same property/characteristicoptions disclosed for recovery filter 223. A recovery port valve 1122 vis secured to port 1122 on a side of recovery filter 1123 distal fromlower end 1116. Valve 1122 v is maintained in a closed position duringnormal filtering operations and is opened to permit the introduction ofpressurized gas to recover filtered liquids resident in the filter core(or to function as a vent).

An upstream vent port 1124 also extends from upper end 1114 to vent anupstream internal volume 1134 described in more detail below. Lastly, anoptional upstream drain port (not shown) may be included and extend fromlower end 1116 to drain liquids from upstream internal volume 1134. Thisgeneral external configuration of filter assembly 1110 is similar tofilter assembly 510 of FIG. 5, with the exception of the absence of anupstream drain port and the location of ports 1122 compared with thelocation of port 522, which is reoriented to lower end 1116 due to theuse of tube 1160.

As previously disclosed, filter shell wall 1112 defines internal volume1128 having a plurality of filter elements/cartridges 1130 disposedtherein. The filter elements may have a generally toroidal configuration(such as the pleated filter shown in cross-section) and a hollow core1132. It should be understood that filter elements 1130 may conform toany of the embodiments disclosed herein and be made from any of thematerials disclosed herein for filter elements. Filter elements 1130 maybe secured in any of the disclosed filter housings via thermal or sonicbonding, adhesive, O-ring seals and any combination of these methods aswell as any another other method used to secure filters in housings asare well known in the art. For filter elements in the form of filtercartridges, the cartridges may be secured in the housing in the samemanner and with the same features as disclosed and shown in FIGS. 21 and22.

As previously disclosed, the combination of shell 1111 and a designatedupstream surface of filter elements 1130 define an upstream volume.Unfiltered liquid enters upstream volume 1134 via inlet port 1118 andpasses through liquid permeable filter elements 1130 to hollow cores1132, and then exits filter assembly 1110 through outlet port 1120 asfiltered liquid.

To control the flow of liquids through filter assembly 1110, each of thevarious ports or tubes 1118 through 1124 (and upstream drain ports insome embodiments) may include a dedicated valve therein. Although eachport may be configured with a valve, different embodiments may beconfigured with valves for only some and even none of the ports.Multiple combinations of ports with or without valves are within thecontemplation and scope of the disclosure with respect to this filterassembly embodiment. For purposes of illustration as well as forcompleteness of the disclosure, dedicated valves for selective ports offilter assembly 1110 are designated as valves 1122 v through 1124 v.Valves 1122 v through 1124 v are shown schematically in FIG. 15, and maybe any suitable type of valve known and used in the art.

Tubes 1160 and downstream recovery ports 1122 may be made from the samematerials described and disclosed for tube 1060 and recovery ports 1022.It should be understood that the list of potential materials describedherein are not exhaustive and include those materials commonly used inthe art to construct such features in filter housings and assemblies.

In the embodiment shown in FIG. 15, during normal filtering and recoveryoperations, filter assembly 1110 is operated in the same manner asdisclosed for filter assemblies 210 through 1010. The positions of thevalves present on filter assembly 1110 (open, closed, partially open)during normal filtering and recovery operations are identical to thecorresponding valve positions of the corresponding valves of filterassembly 210 during normal filtering and recovery operations, e.g.,upstream vent port valve 1124 v, and upstream drain port valve 1126 v,if present, (corresponding to upstream vent port valve 224 v andupstream drain port valve 226 v) are commonly closed during the primaryfiltration function. As such, the disclosure regarding the operation offilter assembly 210 for normal (primary) filtering and recoveryoperations is incorporated here by reference.

The configuration of filter assembly 1110 may also perform the intendedliquid filter and recovery functions when the liquid flow is reversedthrough the assembly. It should be understood that to operate filterassembly 1110 in the reverse flow direction, the filter assembly mayhave to be spatially reoriented gravitationally to have reassigned portspositioned in locations to optimize performance with respect to theirreassigned functions. For example, a port reassigned as an outlet portshould be oriented gravitationally in a low or down position relative tothe body of the filter assembly. This requirement may be eliminated insome embodiments if a dip tube (disclosed hereinbelow) is used.

In one possible reverse functional configuration, similar to the reversefunctional configuration disclosed for embodiment 510, the assembly maybe maintained in the orientation shown schematically in FIG. 15, suchthat outlet port 1120, reassigned as an inlet port, remains located atthe gravitational bottom or low position. It should be noted thatreorientation is not necessary for this functional configurationcompared to the orientation shown as the reassigned outlet port islocated at the gravitational bottom or low position in the orientationshown schematically in FIG. 15. Upstream vent port 1124 is reassigned asa downstream recovery port and will incorporate an inline recoveryfilter similar to, or the same as, recovery filter 1123. Recovery port1122 is reassigned as an upstream vent port and often maintained in aclosed condition during the main filtering operation. It should beunderstood, that outlet aspiration tubes 1060, as shown in FIG. 15 anddescribed as extending into a lower end of cores 1132, would provideimproved venting efficiency if they were to extend upwardly toward, andin close proximity to, a top end of cores 1132, similar to aspirationtubes 1360 shown in FIG. 18 and disclosed in further detail below.

The use of recovery filters 1123 on ports 1122 are optional in thisfunctional configuration. When used in this manner, liquid introducedinto port 1120 (with valve 1120 v open, if present), flows into cores1132 (or the lumen of the filter elements if constructed from, forexample, hollow fiber or tubular material), and radially outwardlythrough filter elements 1130 into internal volume 1134 (now a downstreamvolume) and out of the filter assembly through port 1118 as processedliquid. In this functional configuration, any the remaining port(s), ifpresent, is/are maintained in a closed condition (by, for example,closing their associated valve) or could be eliminated from theembodiment, as shown in FIG. 15, as use of additional downstream portsrisk contamination of the downstream filtered liquid when not coupledwith a recovery filter. Once the intended volume of liquid is filteredthrough assembly 1010, valve 1020 v may be closed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 1110 when operated in the reverse direction is the sameas that disclosed for filter assembly 210 when operated in the reversedirection, with the noted exception that in filter assembly 1110, port1124 is reassigned as a downstream recovery port (providing comparablefunctionality to port 226 reassigned as a downstream recovery port infilter assembly 210) and port 1126 is not depicted. Accordingly, theprocedure disclosed for removing filtered and unfiltered liquid fromfilter assembly 210 when operated in a reverse direction is incorporatedhere by reference with respect to filter assembly 1110.

Referring now to FIG. 18, another multi-round filter assembly is shownwith identical features to the embodiment shown in FIG. 15 except theaspiration tubes designated 1360 in filter assembly 1310 extend fromtheir point of entry at a bottom end of a filter shell wall 1312 intofilter cores 1332 and extend upwardly toward, and in close proximity to,a top end of filter elements 1330. These aspiration tubes place thepoint of gas introduction at a higher point in filter cores 1332 thantheir counterpart, relatively short aspiration tubes 1160 in filterassembly 1110. This configuration may improve the efficiency of liquidflow out of filter assembly 1310 by more advantageously introducing gasinto the filter assembly at a location less likely to interfere with theflow of liquid out through core 1332 and outlet 1320.

The function and operation of filter assembly 1310 is essentially thesame as described and disclosed for filter assembly 1110. Thedescription of the construction of filter assembly 1110 also correspondsto the construction of filter assembly 1310. The disclosure of theconstruction, operation and function of filter assembly 1110 is thusincorporated here to describe the construction, operation and functionof filter assembly 1310. It should be noted that the reference characterdesignations for components of filter assembly 1110 correspond to, andmay be transferred to, character designations for components of filterassembly 1310 by removing the second digit “1” of each referencecharacter and replacing it with a “3”.

Referring now to FIG. 19, in another aspect of the disclosure, amulti-round filter assembly shown designated generally as 1410 includesaspiration tubes 1460 that share a common aspiration tube manifold 1462and a single recovery filter 1423 secured to a manifold extension tube1464 with an optional manifold extension tube valve 1464 v also securedto extension tube 1464. The aspiration tubes 1160, tube manifold 1462,extension tube 1464, recovery filter 1423 and optional tube valve 1464 vare all in fluid communication with cores 1432. The remaining featuresof filter assembly 1410 are identical to the features shown in FIG. 18for filter assembly 1310 and could alternatively be constructed withshorter aspiration tubes, similar to assembly 1110 as shown in FIG. 15.More particularly, a housing or shell designated generally as 1211includes a shell wall 1412, and upper end 1414 and a lower end 1416, thecombination of which define an internal chamber in which one or morefilter elements 1430 are secured. Each enclosed filter element defines adownstream designated core 1432 in fluid communication with aspirationtubes 1160 and all the tubes connected to tubes 1160. The function,operation and performance of filter assembly 1410 are the same as forfilter assembly 1310. The description of the function, operation andperformance of filter assembly 1310 is thus incorporated here withrespect to filter assembly 1410.

Referring now to FIG. 20, in a still further aspect of the disclosure, amulti-round filter assembly shown designated generally as 1510 includesdedicated aspirating tubes 1560 and dedicated recovery filters 1523secured to, and in fluid communication with, tubes 1560 that share acommon recovery tube 1564 and optional recovery tube valve 1564 vsecured to recovery tube 1564. The remaining features of filter assembly1510 are identical to the features shown in FIG. 18 for filter assembly1310 and could alternatively be constructed with shorter aspirationtubes, similar to assembly 1110 as shown in FIG. 15. The function,operation and performance of filter assembly 1510 are the same as forfilter assembly 1310. The description of the function, operation andperformance of filter assembly 1310 is thus incorporated here withrespect to filter assembly 1510.

Referring now to FIG. 23, in a yet further aspect of the disclosure, afilter assembly shown designated generally as 1610 incorporates the samefeatures as filter assembly 510 shown in FIG. 5 in a gravitationallyopposite orientation and with the addition of an outlet dip tube 1668.Outlet dip tube 1668 creates a partition within the downstream side ofelement 1630 and is in liquid communication with outlet port 1620 andcore 1632. The partition formed by outlet dip tube 1668 directs fluidintroduced through recovery port 1622 down to the bottom of core 1632before flowing out through dip tube 1668 and through outlet port 1620.This flow path assures that air or gas introduced into recovery port1622 clears all or substantially all liquid from the downstream core1632 as opposed to taking the path of least resistance and flowingdirectly to outlet port 1620 as would be the case if embodiment 510 wereto be used in its opposite gravitational orientation without theaddition of a dip tube 568. The forward function, operation andperformance of filter assembly 1610 are the same as for filter assembly510, where each is operated in the gravitational orientation depicted intheir respective FIGS. 5 and 23. The description of the forwardfunction, operation and performance of filter assembly 510 is thusincorporated here with respect to filter assembly 1610.

To function in the gravitational orientation illustrated in FIG. 23 whenthe flow is reversed through the assembly, a dip tube is connected toinlet port 1618 (reassigned as an outlet port) to assure that air or gasintroduced through upstream vent port 1624 (reassigned as a recoveryport and configured with a recovery filter similar to, or the same as,recovery filter 1623) is forced to the bottom of volume 1634 (now adownstream volume) to allow for the recovery of filtered liquids. Theuse of the dip tube prevents the air or gas from exiting throughreassigned outlet port 1618 without driving filtered liquids out of thedownstream volume 1634. The reverse function, operation and performanceof filter assembly 1610 are the same as those for filter assembly 510,where each is operated in the gravitational orientation depicted inFIGS. 5 and 23, respectively. The description of the reverse function,operation and performance of filter assembly 510 is thus incorporatedhere with respect to filter assembly 1610.

Referring now to FIG. 16, in another aspect of the disclosure, a singlehybrid hydrophilic/hydrophobic filter material, or a dual layer filtermaterial with one layer having hydrophobic characteristics and the otherlayer having hydrophilic characteristics is positioned in an upper endcap of a filter cartridge to provide a functional valve to permit theprocessing of liquids through a process filter and maintain a pressuregradient from an upstream side of a processing filter to a downstreamside of the processing filter when a recovery function is performedafter the main liquid processing function. Use of this “valve”eliminates the need for a recovery port, or similar feature. This filtermay also be used as the recovery filter in the other embodimentsdisclosed herein, which in some applications may eliminate the need fora valve in the other embodiments.

For purposes of clarity and illustration, but not limitation, as used inthe description of embodiments incorporating a hydrophilic/hydrophobicvalve, the terms hydrophilic, hydrophobic, and liquid are used todescribe the function and design of a filter assembly apparatus andmethod for liquid recovery. A liquid or process liquid is defined to bea process liquid that will spontaneously wet-out one type of filtermaterial and not another. A hydrophilic filter material is defined as afilter material that will spontaneously wet-out in the process liquid. Ahydrophobic filter material is defined as a filter material that willnot spontaneously wet-out in the process liquid.

In certain applications, such as the filtration of alcohols orlow-polarity liquids, a filter material with hydrophobic propertiescould be used in place of the hydrophilic filter material, since many ofthese liquids will spontaneously wet-out a hydrophobic filter materialas is well known in the art. In such a case, use of a filter materialwith oleophobic, super-hydrophobic, or other surface properties may berequired to be used in place of the hydrophobic filter material in orderto prevent wetting of the filter material in this position by theprocess liquid. Accordingly, though hydrophilic and hydrophobicfiltration materials and layers are described throughout the disclosure,the use of filter materials and layers with other surface properties(such as oleophobicity and super-hydrophobicity as disclosed above) toprovide the desired selectivity whereas one filtration materialspontaneously wets out in a liquid and one filtration material does notis within the contemplation and scope of the disclosure.

As shown in FIG. 16, a filter assembly shown designated generally as910, includes a housing or shell 911 dimensioned to enclose a filtercartridge 930. An inlet 918, outlet 920 and an upstream vent 924 extendfrom housing 911. Inlet 918 extends from an upper inlet end 914 and maybe aligned with the longitudinal axis of the enclosed filter cartridge930 or may be oriented away from the longitudinal axis to accommodateany spatial requirements. Inlet 918 is in liquid communication with anupstream internal volume 934 of filter assembly 910, as defined by shell911 and an upstream designated surface of filter element 930. Outlet 920extends from a lower outlet end 916 of the filter assembly 910 and is inliquid communication with a core 932 of filter cartridge 930. Upstreamvent 924 extends laterally or radially from an upper end of filterhousing 911 and may be oriented at different angles to accommodatespatial needs.

Each port may have an optional dedicated valve to open and close theports. If present, valve 918 v is attached to inlet 918, valve 920 v isattached to outlet 920 and valve 924 v is attached to upstream vent port924. Multiple combinations of passages and ports with or without valvesare within the contemplation and scope of the disclosure. It should beunderstood that in assembly 910, ends 914 and 916 can be integral toshell wall 912 or can be removable to permit extraction and replacementof the enclosed filter cartridge 930. In the configuration shown, thetwo ends 914 and 916 are shown integral to shell wall 910 by way ofillustration and not limitation, and the integral versus removablenature of ends 914 and 916 and filter cartridge 930 as well as themethods used to seal the assembly (including the seal of cartridgefilter 930) will depend upon the intended use and operating environmentas well as the configuration of the filter element installed therein.Methods used to seal the assemblies of other embodiments disclosedherein may be used also to seal the components of filter assembly 910.

To permit the recovery of liquid held up within filter assembly 910without a dedicated recovery port, a valve filter 970 is used to performa dual filter and valve function. Valve filter 970 may be a combinationhydrophobic/hydrophilic filter material (including a filter materialhaving either a sole hydrophilic or a sole hydrophobic property with asurface modified to have the opposite property), ahydrophobic/hydrophilic dual layer filter material and any combinationsthereof. Valve filter 970 is secured in an upper end cap 931 of filtercartridge 930 and represents one way to eliminate the need for arecovery port such as those disclosed herein. A filtration material withonly hydrophobic functionality may be used in the locations disclosedfor valve filter 970 to permit contaminant-free recovery of liquidwithin the downstream portions of a filter assembly as well asdownstream lines, etc. However, for embodiments that have the valvefunction disclosed in detail below that permits the additional recoveryof upstream unfiltered fluid, use of filtration material with onlyhydrophobic functionality cannot be used as explained and disclosed inmore detail below.

With respect to the use of a filter material at location 970 that hasonly a hydrophobic functionality, it should be understood that althoughsuch a filter material is suitable to perform the downstream recoveryprocess, as disclosed in detail herein, for many of the aspects andembodiments of the liquid recovery assemblies, it will not function as avalve to maintain a pressure gradient from an upstream side 934 ofprocessing filter 930 to a downstream side of the processing filter 930when a recovery function is performed after the main liquid processingfunction. This gradient is required in order to force unfiltered liquidsin upstream side 934 to the downstream side prior to initiating recoveryof the filtered liquids in the downstream side of the assembly.

As shown in FIGS. 16, 25 and 26, filter material used at the location ofvalve filter 970—whether a hydrophobic filtration material or one of thedual-function filtration material embodiments—may be positioned in avariety of different locations on filter cartridge 930 including end cap931, end cap 935 and/or an outlet port receiving segment 933 and performthe same functions described and disclosed herein with limitedmodification to the disclosed recovery methods. The embodimentsdisclosed in FIGS. 16, 25 and 26 may be used in combination with otherfeatures described within this disclosure to improve functionalityand/or efficiency, e.g., dip tube 1668 shown in FIG. 23 in combinationwith the valve filter 970 location shown in FIG. 26). The hydrophiliclayer or portion of valve filter 970 is positioned in direct contactwith the downstream side of filter cartridge 930. This permits thehydrophilic component to be wetted during the main liquid processingprocedure, but will not permit bulk flow through valve filter 970, asthe liquid cannot pass through the hydrophobic component at pressuresbelow the water intrusion pressure (or liquid intrusion pressure). Itshould be understood, that while use of the valve filter in thisorientation provides advantages (such as reducing the likely hood of aliquid-lock on the hydrophobic filter material) it is possible and mayeven be advantageous to orient the valve filter in the reverse directionin some cases and that all orientations are within the contemplation andscope of the disclosure.

By including an appropriately selected hydrophobic filter material,layer, or surface modified hydrophobic layer, the filter material orlayer prevents the bulk migration of liquids from the upstream sidethrough filter cartridge end cap 931 and/or end cap 935 and/or an outletport receiving segment 933 and concurrently maintains a porous andsterile (or otherwise contamination-preventing) barrier between theupstream and downstream sides of filter cartridge 930. By including anappropriately selected hydrophilic filter material or layer that becomeswetted in use, the filter material or layer prevents the bulk migrationof air or gas from the upstream side of cartridge 930 through the filtercartridge end cap 931 and/or end cap 935 and/or an outlet port receivingsegment 933 at pressures below the bubble point of the selectedfiltration material or layer. During the unfiltered liquid recoveryfunction, this enables the filter assembly to maintain a relatively lowpressure on the downstream side of processing filter cartridge 930 and arelatively higher pressure on the upstream side of cartridge 930 todrive liquids held upstream of filter cartridge 930 into the downstreamportion of filter assembly 910 through the processing filter material solong as the pressure differential between the upstream and downstreamsides of cartridge 930 does not exceed the bubble point of thehydrophilic filter material or layer.

During the main liquid processing function, upstream vent valve 924 v ismaintained in a closed position, but may be opened periodically or evencontinuously to evacuate gas or air from the upstream side of cartridge930. To ensure proper functioning, the hydrophobic component of filtervalve 970 is selected to have a liquid intrusion pressure that exceedsthe pressure in the upstream side of filter cartridge 930 during themain liquid processing procedure, for example to accommodate processingconditions from about 1 to about 2 psi up to about 20 to about 30 psidepending on the system constraints and filtration processingconditions. Intrusion pressure is selected by adjusting the pore sizeand/or surface properties (such as surface energy) of the hydrophobicfilter material.

Filtration materials constructed with polytetrafluoroethylene (PTFE),polyvinylidene fluoride (PVDF), and polyethylene with naturallyoccurring low surface energies as well as filtration materials(including those naturally or typically modified to become hydrophilic)that have been modified to achieve low surface energies are known toresist the flow of aqueous liquids (with sufficiently high surfacetensions) and therefore will exhibit an intrusion pressure for suchliquids. The value of the intrusion pressure is further dependent on thepore size of the filtration media. In the case of membranes constructedfrom PTFE, PVDF, and polyethylene, water intrusion pressures exceeding30 psi are typical for membranes of 0.2 μm pore size ratings and below.

Once the main processing function is performed to recover the residentfiltered liquids (resident in filter core 932 and other downstreamlocations), and unfiltered liquids in the upstream internal volume 934,pressurized gas is introduced via inlet 918, or vent 924 via aperistaltic pump, compressed gas source, or like device. It should beunderstood that the valve associated with the port to which the pump orcompressed gas is attached will be open while the other upstream portvalve(s) will be closed so as to permit the creation of a pressuregradient from the upstream side of filter cartridge 930 to thedownstream side. Since the hydrophobic component of valve filter 970will freely permit the passage of gas, it is the hydrophilic portion orlayer of valve filter 970 that will prevent gas from passing from theupstream side of filter cartridge 930 to the downstream side via valvefilter 970 until the bubble point of the hydrophilic component of valvefilter 970 is exceeded. Thus, a pore size for the hydrophilic componentcan be selected to achieve the desired bubble point as is well known inthe art (or cracking pressure of the valve filter).

Filtration materials constructed with hydrophilized polyethersulfone,nylon, cellulose acetate, cellulose nitrate, hydrophilized PVDF,polycarbonate, as well as others well known in the art with pore sizesgreater than or equal to that of the processing filtration material poresize (dependent also on the material properties and morphology) willhave bubble points in a range that lower the gas pressure required tobypass filter cartridge 930 by way of valve filter 970 in comparison tothe gas pressure required to bypass the processing filtration materialitself. The surface energy of the membrane is chosen such that it isspontaneously wetted by the processing liquid and will depend on thematerial chosen as well as the membrane manufacture or modification.Selecting a hydrophilic filtration material with the appropriate bubblepoint ensures a positive pressure gradient from the upstream to thedownstream side to facilitate the forcing of unfiltered liquids inupstream internal volume 934 into the downstream side as filteredliquid.

To evacuate the filtered liquids remaining in core 932, the gas pressureis increased to exceed the bubble point pressure of the hydrophiliccomponent of valve filter 970. This causes gas to flow through valvefilter 970 to force filtered liquids in core 932 into outlet 920 andultimately out of the filter assembly (clearing downstream lines, ifpresent) with the added assistance of gravity should outlet 920 beoriented at a gravitationally lower end of the filter cartridge. Itshould be understood the orientation of the filter cartridge can bereversed with the inlet end positioned lower than the outlet end, or anyrotation of the filter assembly between the two extreme positions toaccommodate any spatial needs in assemblies to which the filter assemblyis attached. In some orientations, it may be necessary or advantageousto implement additional features described within this disclosure toimprove functionality and/or efficiency (e.g. the dip tube 1668 featureshown in FIG. 23 in combination with the valve filter 970 location shownin FIG. 26).

It should be further understood that the functions of the various portscan be reversed wherein outlet 920 is reassigned as an inlet port, inletport 918 is reassigned as an outlet port, core 932 is reassigned as anupstream internal volume and upstream internal volume 934 is reassignedas the downstream side. The orientation of valve filter 970 must bereversed such that the hydrophilic filter material layer or side ofvalve filter 970 is positioned in direct contact with the downstreamside of filter cartridge 930, now volume 934. This will permit thehydrophilic component to be wetted during the main liquid processingprocedure, but will not permit bulk flow through valve filter 970 as theliquids cannot pass through the hydrophobic component. With thisorientation, the valve filter 970 will still perform the intendedfunction.

As previously stated, valve filter 970 may be constructed in a varietyof configurations including a hydrophobic material with one side orlayer modified to be hydrophilic, a hydrophilic material with one sideor layer modified to be hydrophobic, or dual or multi-layer filtermaterials or filter materials with layers dedicated hydrophobic orhydrophilic. The configurations may also take on various alternativessuch as a pleated configuration shown in FIG. 24, with a pleatedhydrophobic or combination hydrophobic/hydrophilic filter material,hydrophobic/hydrophilic dual layer filter material, orhydrophobic/hydrophilic filter material portion 974 sandwiched betweentwo hydrophilic portions 972 joined as seams 976. Section 972 and 974can be sealed by many methods well known in the art, including thermalsealing, ultrasonic thermal sealing, adhesive bonding, thermal meltsealing, solvent bonding and combinations thereof.

Referring now to FIG. 27, in another aspect of the disclosure, amulti-layer hydrophilic/hydrophobic filter subassembly is showndesignated generally as 970. In this multi-layer embodiment, subassembly970 includes a hydrophobic layer 972 and a hydrophilic layer 974arranged in a layer configuration wherein the plane occupied by thelayers is substantially orthogonal to the direction of gas flow shown inFIG. 27 via the arrow in bold. It should be understood the orientationof subassembly 970 relative to the direction of gas/liquid flow can bemodified to accommodate different applications and to address anyspatial requirements. The channel defined as 938 is formed or providedaccording to the specific embodiment in which the valve filter isincorporated. As illustratively shown in FIG. 25, channel 938 is formedas a bore through end cap 931 that receives valve filter subassembly 970and directs the flow through valve membrane 970 in the general directiondepicted by the arrow in FIG. 27.

It should be understood that in some applications of the valve membrane,the layered arrangement shown in FIG. 27 can be reversed if, forexample, the valve were to function as a liquid filter valve rather thana gas valve as may be required in some applications. To function as aliquid filter valve (which restricts the flow of liquid up until acracking pressure defined now by the hydrophobic filter material'sintrusion pressure), the valve could function independent of theorientation of the hydrophilic/hydrophobic filtration media arrangementso long as the hydrophilic filtration material were chosen to providethe desired filtration efficiency and the hydrophobic filtrationmaterial were chosen to provide the appropriate cracking pressure basedon the liquid intrusion pressure for the liquid intruding into the poresof the hydrophobic filtration material.

Referring now to FIG. 28, in a further aspect of the disclosure, acombined hydrophilic/hydrophobic valve and processing filter assemblyshown designated generally as 900 includes a processing filter material930′ having a gap, bore, slit, or other portal configuration that allowsfluid to bypass the processing filter formed therein. A hydrophobicfilter material 972′ is placed over one side of filter material 930′ anda hydrophilic filter material 974′ is placed over the other side offilter material 930′ to form a hydrophilic/hydrophobic valve within theprocessing filter material field. Filtration materials 972′ and 974′ aresecured to processing filter 970′ via thermal or sonic bonding or byother methods for securing filtration materials as disclosed herein orby other methods for securing filtration materials as is known in theart. It should be known that although FIG. 28 depicts hydrophobic filtermembrane 972′ placed over one side of filter material 930′ andhydrophilic filter membrane 974′ placed over the other side of filtermaterial 930′, other configurations are possible in which both materialsare bonded to one or the other side of filter material 930′. In theconfiguration shown, the valve functions to permit the passage of gasesonce the bubble point of the wetted hydrophilic filtration material isexceeded.

Referring now to FIG. 29, in another aspect of the disclosure, a liquidrecovery filter assembly shown generally as 1710 includes many of thecomponents and elements disclosed above for filter assembly 410, i.e., afilter housing or shell designated generally as 1711 having a shell wall1712 and mutually opposed first or upper and second or lower endsdesignated 1714 and 1716, respectively, and defining an internal volume1728. As shown in this illustrative embodiment, a toroidal filterelement 1730 is secured therein. An upstream designated surface offilter element 1730 and surrounding housing 1711 define an upstreamvolume 1734 therebetween. Filter element 1730 has a hollow core 1732.Although not shown, an optional upstream vent port and an optionalassociated upstream vent port valve (such as that shown in FIG. 4) maybe included and extend from upper end 1714. Also not shown, but alsooptional is an upstream or inlet side drain port and an associated drainport valve (such as that shown in FIG. 4) that, if included, extendsfrom lower end 1716.

An upstream or inlet port 1718 of filter assembly 1710 extends radiallyin close proximity to, or from, upper end 1714. A downstream or outletport 1720 extends downwardly from lower end 1716 and substantiallycoaxially from filter housing 1711 although the coaxial orientation canbe displaced to accommodate specific spatial needs. A recovery port 1722extends from upper end 1714 and is in fluid communication with filtercore 1732.

A recovery filter 1723 is secured to port 1722 between the two ends ofthe port and is in fluid communication with a lumen formed by the port.Recovery filter 1723 should be selected from among the same constructionmaterial options and the same property/characteristic options disclosedfor recovery filter 223. A recovery port valve 1722 v is secured to port1722 on a side of recovery filter 1723 distal from upper end 1714. Valve1722 v is maintained in a closed position during normal filteringoperations and is opened to permit the introduction of pressurized airor gas to recover filtered liquids resident in the filter core (or tofunction as a vent). An optional recovery filter protection valve 1725 vmay be secured to vent port 1722 between upper end 1714 and recoveryfilter 1723. Valve 1725 v is maintained in a closed position duringnormal filtering operations to protect recovery filter 1723 from beingwetted by the liquids flowing through filter assembly 1710. Similarvalves may be incorporated into the other embodiments disclosed hereinin order to protect recovery filters from being wetted by the liquidsflowing through the filter assemblies. Multiple combinations of passagesand ports with or without valves are within the contemplation and scopeof the disclosure.

The liquid flow paths through filter assembly 1710 during normalfiltering operations and during the drainage or recovery of filteredliquids from filter assembly 1710 are essentially the same as thosedisclosed above for filter assembly 410. Recovery port valve 1722 v, andto the extent incorporated into the filter assembly, any upstream ventport valve and any upstream drain port valve are closed during normalfiltering operations. To the extent an upstream inlet valve and/or adownstream outlet valve are incorporated into the filter assembly tocontrol flow into inlet 1718 and flow out of outlet 1720, respectively,those optional valves are maintained in an open position to permit flowthrough the filter assembly 1710.

Referring now to FIGS. 29 and 31, liquid recovery filter assembliesshown generally as 1710 and 1910 include many of the same components andfeatures; however, optional upstream vent port 1924 and associatedoptional valve 1924 v as well as optional upstream vent port 1926 andassociated optional valve 1926 v shown in FIG. 31 for embodiment 1910are not depicted in FIG. 29 for embodiment 1710. As all accessory ventand drain ports are optional, the function of 1710 and 1910 areessentially the same, and the reference character designations forfilter assembly 1710 correspond to, and may be transferred to, filterassembly 1910 by removing the second digit “7” of each referencecharacter and replacing it with a “9”.

During normal filtering and recovery operations, filter assemblies 1710and 1910 are operated in the same manner as disclosed for filterassembly 410 and other similar assemblies. The positions of the valvespresent on filter assemblies 1710 and 1910 (open, closed, partiallyopen) during normal filtering and recovery operations are identical tothe corresponding valve positions of the corresponding valves of filterassembly 410 during normal filtering and recovery operations, e.g.,upstream vent port valve 1724 v or 1924 v, if present, and upstreamdrain port valve 1726 v or 1926 v, if present, (corresponding toupstream vent port valve 424 v and upstream drain port valve 426 v) arecommonly closed during the primary filtration function. As such, thedisclosure regarding the operation of filter assembly 410 for normal(primary) filtering and recovery operations is incorporated here byreference.

The configuration of filter assemblies 1710 and 1910 may also performthe intended liquid filter and recovery functions when the liquid flowis reversed through the assembly. It should be understood that tooperate filter assemblies 1710 and 1910 in the reverse flow direction,the filter assemblies may have to be spatially reorientedgravitationally to have reassigned ports positioned in locations tooptimize performance with respect to their reassigned functions. Forexample, a port reassigned as an outlet port should be orientedgravitationally in a low or down position relative to the body of thefilter assembly. This requirement may be eliminated in some embodimentsif a dip tube (disclosed herein) is used.

In one possible reverse functional configuration, the assembly isreoriented such that outlet port 1720 or 1920, reassigned as an inletport, is located at the gravitational top or high position. Optionalupstream drain port 1726 or 1926 and, if present, optional drain portvalve 1726 v or 1926 v, are reassigned as a downstream recovery port andoptional downstream recovery port valve, respectively, and willincorporate an inline recovery filter similar to, or the same as,recovery filter 1723 or 1923. Recovery port 1722 or 1922 and, ifpresent, optional recovery port valve 1726 v or 1926 v are reassigned asan upstream drain port and optional reassigned upstream drain portvalve, respectively, and often maintained in a closed condition duringthe main filtering operation.

The use of a recovery filter 1723 or 1923 on port 1722 or 1922 isoptional in this functional configuration and may need to be removed incertain cases, as disclosed above. When used in this manner, liquidintroduced into port 1720 or 1920 (with valve 1720 v or 1920 v open, ifpresent), flows into core 1732 or 1932 (or the lumen of the filterelement if constructed from, for example, hollow fiber or tubularmaterial), and radially outwardly through filter element 1730 or 1930into internal volume 1734 or 1934 (now a downstream volume) and out ofthe filter assembly through port 1718 or 1918 as processed liquid. Inthis functional configuration, the remaining port(s) (port 1724 or 1924in the embodiment shown in FIG. 31, but not in FIG. 29) is/aremaintained in a closed condition (by, for example, closing valve 1724 vor 1924 v in the embodiment shown in FIG. 31, but not shown in FIG. 29),or could be eliminated from the embodiment, as use of these ports riskcontamination of the downstream filtered liquid when not coupled with arecovery filter.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 1710 or 1910 when operated in the reverse direction isthe same as that disclosed for filter assembly 410 when operated in thereverse direction. Accordingly, the procedure disclosed for removingfiltered and unfiltered liquid from filter assembly 410 when operated ina reverse direction is incorporated here by reference with respect tofilter assembly 1710 or 1910.

Referring now to FIG. 30, in another aspect of the disclosure, a liquidrecovery filter assembly shown generally as 1810 includes many of thecomponents and elements disclosed above for filter assembly 1710, withthe primary difference being the orientation of the inlet port and theoutlet port. In filter assembly 1710, the ports are arranged in a “T”configuration with inlet port 1818 occupying substantially the sameplane as outlet port 1820, similar to the embodiment 510 of FIG. 5. Inthis configuration, inlet port 1818 extends radially outwardly from abottom end of filter assembly 1810 while outlet port 1820 extendsradially outwardly from the bottom end in a direction substantiallyopposite the direction of inlet port 1818. It should be understood thatthe relative orientation and direction of the two ports can be modifiedto extend radially from a variety of different orientations toaccommodate any particular application or spatial requirement.

A filter housing or shell 1811 having a shell wall 1812 with mutuallyopposed first or upper and second or lower ends designated 1814 and1816, respectively, collectively define an internal volume 1828. Atoroidal filter element 1830 is secured therein. An upstream designatedsurface of filter element 1830 and surrounding housing 1811 define anupstream or inlet volume 1834 therebetween. Filter element 1830 has ahollow core 1832. Although not shown, an upstream vent port and anoptional associated upstream vent port valve (such as that shown in FIG.5) may be included and extend from upper end 1814. Also not shown, butalso optional is an upstream drain port and an optional associated drainvalve (such as that shown in FIG. 5) that, if included, extends from thelower or downstream end 1816.

A recovery port 1822 extends from upper end 1814 and is in liquidcommunication with filter core 1832. A recovery filter 1823 is securedto port 1822 between the two ends of the port and is in fluidcommunication with a lumen formed by the port. Recovery filter 1823should be selected from among the same construction material options andthe same property/characteristic options disclosed for recovery filter223. A recovery port valve 1822 v is secured to port 1822 on a side ofrecovery filter 1823 distal from upper end 1814. Valve 1822 v ismaintained in a closed position during normal filtering operations andis opened to permit the introduction of pressurized gas to recoverfiltered liquids resident in the filter core. An optional recoveryfilter protection valve 1825 v may be secured to recovery port 1822between upper end 1814 and recovery filter 1823. Valve 1825 v ismaintained in a closed position during normal filtering operations toprotect recovery filter 1823 from being wetted by the liquids flowingthrough filter assembly 1810. Similar valves may be incorporated intothe other embodiments disclosed herein in order to protect recoveryfilters from being wetted by the liquids flowing through the filterassemblies. Multiple combinations of passages and ports with or withoutvalves are within the contemplation and scope of the disclosure.

The liquid flow paths through filter assembly 1810 during normalfiltering operations and during the drainage or recovery of filteredliquids in filter assembly 1810 are essentially the same as thosedisclosed above for filter assembly 510. Recovery port valve 1822 v, andto the extent incorporated into the filter assembly, any upstream ventport valve and any upstream drain port valve are closed during normalfiltering operations. To the extent an inlet valve and/or an outletvalve are incorporated into the filter assembly to control flow intoinlet 1818 and flow out of outlet 1820, respectively, those optionalvalves are maintained in an open position to permit flow through filterassembly 1810.

Referring now to FIGS. 30 and 32, liquid recovery filter assembliesshown generally as 1810 and 2010 include many of the same components andfeatures, however, optional upstream vent port 1824 and associatedoptional valve 1824 v as well as optional upstream vent port 1826 andassociated optional valve 1826 v shown in FIG. 30 for embodiment 1810are not depicted in FIG. 32 for embodiment 1810. As all accessory ventand drain ports are optional, the function of 1810 and 2010 areessentially the same, and the reference character designations forfilter assembly 1810 correspond to, and may be transferred to, filterassembly 2010 by removing the first and second digits “18” of eachreference character and replacing them with a “20”.

During normal filtering and recovery operations, filter assemblies 1810and 2010 is operated in the same manner as disclosed for filter assembly510. The positions of the valves present on filter assembly 1810 and2010 (open, closed, partially open) during normal filtering and recoveryoperations are identical to the corresponding valve positions of thecorresponding valves of filter assembly 510 during normal filtering andrecovery operations, e.g., upstream vent port valve 1824 v and 2024 v,and upstream drain port valve 1826 v and 2026 v (corresponding toupstream vent port valve 524 v and upstream drain port valve 526 v) arecommonly closed during the primary filtration function. As such, thedisclosure regarding the operation of filter assembly 510 for normal(primary) filtering and recovery operations is incorporated here byreference.

The configuration of filter assembly 1810 and 2010 may also perform theintended liquid filter and recovery functions when the liquid flow isreversed through the assembly. It should be understood that to operatefilter assembly 1810 and 2010 in the reverse flow direction, the filterassembly may have to be spatially reoriented gravitationally to havereassigned ports positioned in locations to optimize performance withrespect to their reassigned functions. For example, a port reassigned asan outlet port should be oriented gravitationally in a low or downposition relative to the body of the filter assembly. This requirementmay be eliminated in some embodiments if a dip tube (disclosedhereinbelow) is used.

In one possible reverse functional configuration, again, similar to thatdisclosed for 510, the assembly may be maintained in the orientationshown schematically in FIGS. 30 and 32, such that outlet port 1820 or2020, reassigned as an inlet port, remains located at the gravitationalbottom or low position. It should be noted that reorientation is notnecessary for this functional configuration compared to the orientationshown as the reassigned outlet port is located at the gravitationalbottom or low position in the orientation shown schematically in FIGS.30 and 32. Upstream vent port 1824 or 2024 is reassigned as a downstreamrecovery port and will incorporate an inline recovery filter andoptional associated recovery filter valves and recovery filterprotection valves similar to, or the same as, recovery filter 1823 or2023 and optional associated valves. Recovery port 1822 or 2022 isreassigned as an upstream vent port and often maintained in a closedcondition during the main filtering operation.

The use of a recovery filter 1823 or 2023 on port 1822 or 2022 isoptional in this functional configuration. When used in this manner,liquid introduced into port 1820 or 2020 (with valve 1820 v or 2020 vopen, if present), flows into core 1832 or 2032 (or the lumen of thefilter element if constructed from, for example, hollow fiber or tubularmaterial), and radially outwardly through filter element 1830 or 2030into internal volume 1834 or 2034 (now a downstream volume) and out ofthe filter assembly through port 1818 or 2018 as processed liquid. Inthis functional configuration, the remaining port(s), if present, (port1826 or 2026 in the embodiment shown in FIG. 32 but not shown in FIG.30) is/are maintained in a closed condition (by, for example, closingvalve 1826 v or 2026 v in the embodiment shown in FIG. 32 but not shownin FIG. 30) or could be eliminated from the embodiment, as use of theseports risk contamination of the downstream filtered liquid when notcoupled with a recovery filter. Once the intended volume of liquid isfiltered through assembly 1810 or 2010, valve 1820 v or 2020 v may beclosed to cease flow.

The procedure to remove the resident unfiltered and filtered liquidwithin assembly 1810 or 2010 when operated in the reverse direction isthe same as that disclosed for filter assembly 510 when operated in thereverse direction. Accordingly, the procedure disclosed for removingfiltered and unfiltered liquid from filter assembly 510 when operated ina reverse direction is incorporated here by reference with respect tofilter assemblies 1810 or 2010.

Referring now to FIGS. 33 and 34, in another aspect of the disclosure, arecovery filter protection valve assembly is incorporated into a liquidrecovery filter assembly designated generally as 2110. The recoveryfilter protection valve assembly shown on assembly 2110 is meant to beillustrative and not limiting with respect to recovery filter protectionvalve assemblies suitable for use in the disclosed filter assemblies.Filter assembly 2110 includes many of the same features as priordisclosed embodiments including a housing or shell 2111 having a shellwall 2112 with an upper end 2114 and a lower end (not shown) that incombination define an internal volume 2128. A filter element 2130 havinga downstream core 2132, or other type of filter element, as disclosedherein, is secured in internal volume 2128 with any of the methods forsecuring filter elements disclosed herein. Filter assembly 2110 mayinclude any or all of the upstream and/or downstream ports and optionalassociated valves disclosed with respect to other filter assemblyembodiments disclosed herein.

Filter assembly 2110 also includes a recovery port 2122 thatincorporates an in-line recovery filter protection valve body 2150between recovery filter 2123 and core or downstream volume 2132. Acollapsible recovery filter protection valve tube 2152 is containedwithin valve body 2150 and defines the flow path through valve body2150. A recovery filter 2123 is secured in-line with port 2122 and is influid communication with filter core 2132 via port 2122 and tube 2152.Recovery filter 2123 should be selected from among the same constructionmaterial options and the same property/characteristic options disclosedfor recovery filter 223.

Valve body 2150 extends upwardly from upper end 2114 and may terminateat any point between volume 2132 and recovery filter 2123. Valve body2150 defines a chamber to attach to port 2122 and to provide a surfaceto assist compression of tube 2152. A bore 2151 is formed in a sidewallof body 2150 to receive a tube compression bolt or pin 2154. Bolt 2154may include threading with corresponding mated threading formed on thesurface of bore 2151. It should be understood that the method used toadvance and retract bolt 2154 may be accomplished by other methods suchas bolt treading and a retainer clip secured inside body 2150 with abore dimensioned to engage the threading of bolt 2154. Tube 2152 iscompressed by torqueing bolt 2154 onto a sidewall of tube 2152 so as tocompress the sleeve against the inner wall of body 2150 as shown in FIG.34. To reopen the tube lumen, bolt 2154 is backed off tube 2152 as shownin FIG. 33. An optional rigid, or otherwise protective material, notshown, may be included between bolt 2154 and tube 2152 to protect tube2152 from damage and wear caused by contact or interaction with bolt2154. The cylindrical edge of the terminus of bolt 2154 may be radiusedto prevent the edge from tearing into tube 2152 when compressed againstthe tube.

A first or lower end of recovery port 2122 extends from upper end 2114and is in fluid communication with core 2132 of filter element 2130.Filter element 2130 is secured in housing 2111 by any of the meansdisclosed herein including mated surfaces with O-rings, thermal or sonicwelding, adhesive and the like. The same methods to join the componentstogether may be used if a filter cartridge is secured in shell housing2111. A second or upper end of the recovery port 2122 extends above orbeyond a top surface of body 2150. Recovery filter 2123 is securedwithin a top end of recovery port 2122 and is in fluid communicationwith a lumen of recovery port 2122. It should be understood that body2150 may be dimensioned to house recovery filter 2123 within its bordersand may be used to eliminate the need for a capsule to enclose recoveryfilter 2123.

Tube 2152 may be secured to port 2122 by dimensioning an internalcross-sectional diameter of tube 2152 to be greater than the outercross-sectional diameter of port 2122. Tube 2152 is then slipped ontothe outer wall of port 2122 and secured by the elasticity of thematerial used to construct tube 2152 that constricts onto tube 2122.Barbs, adhesives, thermal and/or sonic bonding, other methods disclosedherein as well as any method known in the art for connecting fluidpathways may also be used. It should be understood that the dimensionalorientation of the parts may be reversed whereby the outsidecross-sectional diameter of tube 2152 is smaller than the innercross-sectional diameter of port 2122. In this configuration, tube 2152is inserted into port 2122 and secured with adhesive, thermal and/orsonic bonding, crimping and the like as well as any method disclosedherein or known in the art for connecting tubular fluid pathways. Themeans to join the two tubular elements may include another tube (notshown) that functions as an internal or external coupling sleeve, or asan additional component inserted into or around an outer surface of port2122 and tube 2152.

The materials used to make tube 2152 may be chosen to be the samematerials of construction used for the shell, end caps, ports of thefilters disclosed herein and may include, but are not limited to,polypropylene, polyethylene, nylon, polyester, fluoropolymers, metalsand metallic alloys, etc. It is important to select a materials thatwill not react to, or interact with, the materials intended to beintroduced into the filter assembly.

Referring now to FIGS. 35 and 36, in yet another aspect of thedisclosure, a liquid recovery filter assembly shown designated generallyas 2210 includes essentially the same corresponding features of filterassembly 2110 except bolt 2154 is not present in this embodiment. Toopen and close tube 2252, a lever control 2254 is used.

A recovery filter protection valve body 2250 is dimensioned to receivelever control 2254. Lever control 2254 is secured to body 2250 via anaxle (not shown) about which control 2254 can rotate from a closedposition (tube compression position shown in FIG. 36) to an openposition (tube open position shown in FIG. 35). Stops may beincorporated into body 2250 to limit the range of motion of levercontrol 2254. A slot is formed in body 2250 to receive the axle andoptional bearing used to secure lever control 2254 and to permit freerotation about the axle. A tube impinging segment 2259 is positionedinside body 2250. A lever operating segment 2257 extends from the axleoutside body 2250. In an open position, tube impinging segment 2259 iseither disengaged from tube 2252 or in registration against it, but notcompressing the tube to an extent that would restrict flow through thelumen within tube 2252. In a closed position, impinging segment 2259 isregistered against tube 2252 and compressing it against an inner wall ofpost 2250 to close the lumen and prevent fluid and/or gas flow throughthe sleeve. An optional rigid, or otherwise protective material, notshown, may be included between impinging segment 2259 and tube 2252 toprotect tube 2252 from damage and wear caused by contact with andimpingement by 2259. Any surface of impinging segment 2259 that contactstube 2252 may be radiused to prevent tearing of the tube.

The orientation of impinging segment 2259 is determined by the operationand orientation of operating segment 2257. In an open position,operating segment is in an “up” position as shown in FIG. 35. In aclosed position, operating segment 2257 is in a “down” position shown inFIG. 36. It should be understood that the orientation of lever 2254 canbe reversed on the axle whereby the operating segment is in a “down”position in the open position and in an “up” position in the closedposition. Lever 2254 can be manually or automatically operating with astep motor and the like.

Referring now to FIG. 37, in a further aspect of the disclosure, aliquid recovery filter assembly shown designated generally as 2310includes essentially the same corresponding features as most of theembodiments disclosed herein with the addition of a check valve 2352secured in a downstream recovery port 2322 between a recovery filter2323 (similar to, or the same as, recovery filter 223) and a filter coreor downstream volume 2332 rather than a conventional valve or thecollapsible valves of filter assembly embodiments 2110 and 2210. Thecheck valve provides a means for limiting liquid and/or gas flow to onedirection, into the core. This enables the filtered liquid to berecovered by introducing a gas through recovery port 2322 into recoveryfilter 2323 and into core 2332. Check valve 2352 prevents fluids fromflowing into filter 2323.

The materials used to construct valve 2352 include natural and syntheticrubbers, elastomers, plastics, and other materials disclosed herein aswell as other materials known in the art to construct one-way valves. Aswith other features of the disclosed embodiments, material selectionshould take into account the liquids and gases that will contact thevalve.

Referring now to FIGS. 38 and 39, in a still further aspect of thedisclosure, a liquid recovery filter assembly shown designated generallyas 2410 includes a check valve 2452 to prevent flow between a filterelement core 2432 and a recovery filter 2423 (similar to, or the sameas, recovery filter 223). Check valve 2452 includes an upper (closest torecovery filter 2423) porous or otherwise non-contiguous layer 2456secured in and fully integral with recovery port 2422 such that allfluid passing from filter 2423 to core 2432 must pass through the poresor openings in layer 2456. A lower non-porous or otherwiseflow-restrictive layer 2458 is secured to upper layer 2456 at one ormore points such that it is held in position, but may be bent or angledaway from layer 2458 if force is applied. In FIG. 39, it is shown that acenter section of layer 2458 is secured to upper layer 2456, while anouter annular (or other shape) segment 2460 of lower layer 2458 is freeto rotate or bend away from upper layer 2456, and is dimensioned tocontact the inner wall of recovery port 2322 when flattened againstupper layer 2456 so as to create a seal when in a closed position.

Operation of valve 2452 is determined by pressure gradient. Duringregular filtering operations with the processing filter, a pressuregradient is created with a higher pressure below the valve and a lowerpressure above the valve as shown in FIG. 39. This pressure gradientcauses segment 2460 to remain in a closed position and prevent liquidsin the downstream side of the processing filter from gaining access torecovery filter 2423.

Following the primary filtering operation, to recover filtered liquidsremaining in the downstream side, pressurized gas is introduced intorecovery port 2422 and flows through check valve 2452. The addition ofthe pressurized gas reverses the pressure gradient to now have thehigher pressure on the upper side of valve 2452. This causes segment2460 to rotate or bend downwardly so as to permit the gas to pass beyondvalve 2452 and into downstream volume or core 2432. Any sudden reversalof the pressure gradient will cause the segment 2460 to rotate or bendback up into a closed position and protect recovery filter 2423 from theliquids in the filter assembly.

Upper layer 2456 may be constructed from the same materials ofconstruction used for the shell, end caps and ports of the filterassemblies disclosed herein and may include, but are not limited to,polypropylene, polyethylene, nylon, polyester, fluoropolymers, metalsand metallic alloys, etc. Further, upper layer 2456 may be constructedas a recovery filter using the same materials and considerationsdisclosed for recovery filter 223. If layer 2456 is constructed as arecovery filter with properties capable of ensuring the purity of fluidspassing through layer 2456 are appropriate for contact with the filteredliquid, recovery filter 2423 can be eliminated from recovery port 2422.Additional supportive layers or materials may be necessary to providestructural as well as fluid integrity to layer 2423, if constructed as arecovery filter. Lower layer 2458 may be constructed from natural andsynthetic rubbers, elastomers, plastics, and other materials disclosedherein as well as other materials known in the art to construct one-wayvalves. As with other embodiments, material selection should take intoaccount the liquids and gases the materials will contact.

Referring now to FIG. 40, in yet another aspect of the disclosure, aliquid recovery filter assembly shown designated generally as 2510includes an upstream vent port 2524 coaxially arranged with a downstreamrecovery port 2522. This embodiment provides an additional means toreduce the overall size of the filter assembly when external spatialrequirements require a more compact filter assembly design.

Filter assembly 2510 includes most of the features of the other filterassembly embodiments disclosed herein including a housing or shell 2511,shell wall 2512, internal volume 2528, upper housing end 2514, lowerhousing end 2516, filter element 2530 secured in the housing, filtercore 2532, inlet port 2518, outlet port 2520 and recovery filter 2523(similar to, or the same as, recovery filter 223), secured in line andin fluid communication with the lumen of downstream recovery port 2522.It should be understood that although this embodiment is shown in the“T” configuration (inlet and outlet ports orientation), the coaxialupstream and downstream vent and recovery ports can be incorporated intoany of the other filter assembly configurations disclosed herein.

As shown, filter assembly 2510 includes upstream vent port 2524 thatextends from upper end 2514 and is dimensioned to enclose recoveryfilter 2523 and downstream recovery port 2522. A distal end of port 2524includes a barb 2525 to receive a hose/tube or other further assembly.Quick connects, sterile clamps and the like may also be secured toupstream vent port 2524. In this configuration, vent port 2524 may beused to integrity test the filter assembly.

Downstream recovery port 2522 is connected to and/or in fluidcommunication with filter core 2532. The method to connect port 2522 tocore 2532 is the same as disclosed for other filter assembly embodimentsdisclosed herein. Port 2522 has a cross-sectional diameter smaller thanthe cross-sectional diameter of upstream vent port 2524 and is arrangedin a substantially coaxial arrangement with a shared longitudinal axis.It should be understood that downstream recovery port 2522 may be offsetso as to have an independent axis and remain contained within upstreamvent port 2524. An optional stabilizing ring 2570 may be secured to, orin close proximity to, upper end 2514 and to downstream recovery port2522 to stabilize the port in the filter assembly. Ring 2570 is formedwith slots or perforations to permit liquids and/or gases to passbetween an upstream volume of the filter assembly and upstream vent port2524.

Recovery filter 2523 is secured to downstream recovery port 2522 withinthe inner wall of upstream vent port 2524. An annular gap exists betweenthe perimeter of filter 2523 and the inner wall of port 2524 to permitfluid and/or gas flow in the port. Alternatively, the capsule forrecovery filter 2523 may be secured to the inner wall of upstream ventport 2524 at one or more points to add structural support. Gaps betweenthe contact/connection points provide the pathways for fluid/gas flowthrough upstream vent port 2524. A distal end of downstream recoveryport 2522 includes a downstream vent barb 2527 to receive a hose/tube orother further assembly. Quick connects, sterile clamps and the like mayalso be secured to downstream recovery port 2522.

Referring now to FIGS. 41, 42, 46-49, 53-56 and 59-65 in yet anotheraspect of the disclosure, a liquid recovery filter assembly showndesignated generally as 2610 includes a recovery filter subassemblysecured within the assembly's housing or shell so as to provide a morecompact filter assembly and to provide additional structural protectionfor the recovery filter. Filter assembly 2610 includes many of the samefeatures as the other filter assembly embodiments disclosed herein. Ahousing or shell 2611 having a shell wall 2612 with an upper end orupper end cap 2614 and a lower end or lower end cap 2616 that, incombination, define an internal volume 2628. As shown in FIGS. 41 and42, shell 2611 is a two-piece design with the shell ends being integralto one half, or one section of shell wall 2612, the two sections ofwhich are secured together via thermal bonding, or other method to formthe shell wall. It should be understood that shell 2611 may also beformed with a single piece shell wall with one integral end and one endcap, or with two end caps. A filter element 2630 having a downstreamcore 2632 is secured in internal volume 2628. An inlet port 2618 is influid communication with an inlet channel 2619 and with an upstreamportion 2634 of internal volume 2628 (defined by the inner surfaces ofshell wall 2612, upper end 2614, outlet end or end 2616 and an outerupstream designated surface of filter element 2630). An outlet port 2620is in fluid communication with filter core 2632.

In the embodiment shown, filter assembly 2610 has an upstream vent portsubassembly 2624, an upstream drain port subassembly 2626 and adownstream liquid recovery port subassembly 2622 that also functions asa downstream vent port. Each port includes an optional bleed valve witheach valve having a valve stem, valve adjustment cap and O-ring(s) tocreate sliding seals as disclosed in more detail below.

Filter element 2630 may be in a cartridge form wherein a filter cagedesignated generally as 2631 is superposed about the filter media anddefines an upstream boundary of the filter media portion of the filterelement. Cage 2631 is formed from non-porous materials such as thosedisclosed herein as being suitable for formation of the various filterassembly housing embodiments. Cage 2631 is formed with bores, channelsand/or a lattice-like structure to permit liquids and gases to pass fromupstream volume 2634 into the enclosed filter material. An upper cageend cap 2637 is secured to, or integral with, filter cage 2631 and isformed from a non-porous material like cage 2631 with or without boresand/or channels, or a lattice-like structure to permit liquidtransmission from the upstream side to the filter material inside thecage. A lower cage end cap 2637 a is secured to, or integral with,filter cage 2631 and is formed also from a non-porous material like cage2631 with or without bores and/or channels, or a lattice-like structureto permit liquid transmission from the upstream side to the filtermaterial inside the cage. The filter cage and filter cage end capscollectively define a filter cartridge chamber within which is securedfilter material. The enclosed filter material may be thermally bonded toone or both end caps, or alternatively, may be potted at one or bothends with an adhesive to form a smooth continuous surface for one orboth end caps.

Filter element 2630 has additional features to secure the cartridge tohousing 2611. Specifically, a lower hollow post 2633 extends downwardlyfrom a main body of filter element 2630. An inner wall of post 2633defines a post lumen in liquid communication with filter core 2632 andoutlet channel 2621. Lower end or end cap 2616 has a filter cartridgelower receiving sleeve 2635 with an inner diameter dimensioned toreceive lower post 2633. A lower O-ring annular channel 2639 is formedon the outer surface of post 2633 and/or an inner surface of sleeve 2635to receive a lower O-ring 2641 to form a substantially liquid-tight,friction-type and/or compressive-type seal between the sleeve and thepost. The channel defined by sleeve 2635 is in fluid communication withcore 2632 and outlet port 2620. It should be understood that the postand sleeve combination as disclosed for this embodiment can be formedalso in an opposite configuration with the hollow post formed on thelower end, or end cap and the sleeve formed on filter element 2630. Itshould also be understood that other methods disclosed herein as well asother methods known in the art (e.g., a luer lock design) can be used toconnect upper and/or lower ends of element 2630 to shell or housing 2611and remain within the scope of the disclosure.

With respect to alternative methods to secure filter cartridge 2630,lower post 2633 may be permanently secured to lower end 2616, or to aninner wall of outlet port 2620 as shown and disclosed in more detailherein. The means used to permanently secure post 2633 to the sleeve oflower end 2616 (or the opposite sleeve and post alternative disclosedabove) include thermal or sonic bonding, adhesive as well ascombinations of the different bonding methods. The use of a permanentmethod of bonding the cartridge to the housing eliminates the need foran O-ring seal and any modifications necessary to incorporate an O-ringseal.

An upper filter element sleeve or bore 2643 is formed on a top end offilter element 2630 and is dimensioned to receive a segment of arecovery filter subassembly designated generally as 2623, disclosed indetail below. Alternatively, the upper portion of filter element 2630can be configured as a hollow upper post (not shown) such as lower post2633 to receive recovery filter subassembly 2623. It should also beunderstood that other methods disclosed herein as well as other methodsknown in the art can be used to connect the upper and/or the lower endsof element 2630 to shell 2611 and remain within the scope of thedisclosure. By way of illustration, the methods used to permanentlysecure lower post 2633 to the lower end cap or outlet port may also beused with respect to sleeve 2643 or the alternative upper postconfiguration. An O-ring seal may also be used as disclosed in moredetail herein.

Recovery filter subassembly shown designated generally as 2623 isdimensioned to fit within housing 2611. Subassembly 2623 has a recoveryfilter housing, capsule or shell 2670 having portions defining arecovery filter chamber 2672 dimensioned to receive and support arecovery filter 2674 (at least functionally similar to, or the same as,recovery filter 223). Housing 2670 has further portions defining a fluidchannel 2677 in fluid communication with processing filter core 2632 andwith a lumen or channel of a recovery port 2622 a. Subassembly 2623 hasa hollow core receiving lower post 2678 a extending downwardly fromhousing 2670 and proximal to filter cartridge 2630. Post 2678 a isdimensioned to fit within sleeve 2643 and has an annular channel 2680 aformed in an outer surface dimensioned to receive an O-ring 2682 tocreate a substantially liquid-tight, friction-type seal between thesleeve and the post. O-ring 2682 is seated in channel 2680 and has anouter surface that registers against an inner wall of sleeve 2633 tocreate the seal.

It should be understood that channel 2680 a may also be formed on theinner wall of sleeve 2643 to receive the O-ring and have an innersurface of the O-ring register against a substantially smooth outersurface of lower post 2678 a. Moreover, more than one O-ring and/orO-ring/channel combination may be used to secure each post and sleevecombination as shown in FIG. 22. It should be further understood thatother means known in the art to attach recovery filter subassembly 2623to filter element 2630 may be used and remain with the scope of thedisclosure.

With respect to other methods to secure filter subassembly 2623 tofilter element 2630, as shown in FIGS. 63 and 65, post 2678 a may bepermanently sealed to sleeve 2643. The means used to permanently securepost 2678 a to sleeve 2643 (or the opposite sleeve and post alternativedisclosed above) include thermal or sonic bonding, adhesive as well ascombinations of the different bonding methods. The use of a permanentmethod of bonding filter cartridge 2630 to recovery filter assembly 2623eliminates the need for an O-ring seal and any modifications necessaryto incorporate an O-ring seal such as channel 2680 a.

Subassembly 2623 further has a hollow upper post 2684 that extendsupwardly from housing 2670 and distal from filter core 2632 to provide astructural means to secure subassembly 2623 to filter assembly upper endor upper end cap 2614. Upper post 2684 has portions defining an annularupper O-ring channel 2675 formed on an outer wall and dimensioned toreceive an O-ring 2686 secured therein. Upper end cap 2614 has portionsdefining a sleeve 2615 dimensioned to receive upper post 2684 and O-ring2686. O-ring 2686 registers against an inner wall of sleeve 2615 so asto create a substantially liquid-tight, friction-type and/orcompressive-type seal between subassembly 2623 and upper end 2614. Itshould be understood that upper O-ring channel 2675 can be formedinstead on the inner wall of sleeve 2615 to receive the O-ring, an innersurface of which will register against an outer wall of upper post 2684to create the seal. Other means disclosed herein or known in the art mayalso be used to secure subassembly 2623 to upper end 2614 and remainwithin the scope of the disclosure.

With respect to other methods to secure filter subassembly 2623 to upperend 2614, as shown in FIGS. 64 and 65, post 2684 may be permanentlysealed to sleeve 2615. The means used to permanently secure post 2684 tosleeve 2615 (or the opposite sleeve and post alternative disclosedabove) include thermal or sonic bonding, adhesive as well ascombinations of the different bonding methods. The use of a permanentmethod of bonding filter assembly upper end cap 2615 to recovery filterassembly 2623 eliminates the need for an O-ring seal and anymodifications necessary to incorporate an O-ring seal such as channel2675.

To maintain a fluid path from core 2630 to the lumen or channel ofrecovery port 2622 a, the depth of upper end or upper end cap sleeve2615 is dimensioned to be greater than the length of upper post 2684 soas to create a gap that connects the fluid path from the lumen ofrecovery port 2622 a to channel 2677. In this configuration, an uppersurface of the main body of recovery filter subassembly 2623 registersagainst an annular shoulder defined by a lower edge of upper sleeve2615. In an alternative embodiment, the depth of sleeve 2615 can bedimensioned to be the same as the length of upper post 2684 so that atop end of the post registers against a bottom of sleeve 2615. In thisconfiguration, a radial channel (not shown) is formed on a top end ofupper post 2684 to connect the lumen of recovery port 2622 a to channel2677 and any channels disclosed herein as being therebetween.

The combination of upper end or end cap 2614, recovery filtersubassembly 2623 and the upper portion of filter element 2630 providethe means to anchor the top end of filter element 2639 to housing 2611.It should be understood for embodiments that present the recovery filterin-line with the recover port, outside the filter assembly housing, thatthe same sleeve/post configuration used to secure the recovery filtersubassembly inside the housing can also be used to secure the upper endof the filter element directly to the housing without the use ofO-rings. FIGS. 63-65 show illustrative examples of one post (FIGS. 63and 64), or both (FIG. 65) posts of recovery filter assembly 2623permanently fixed, i.e., without an O-ring seal. Other constructionalternatives to secure the filter element to the filter housing aredisclosed hereinbelow.

The internalization of recovery filter subassembly 2623 does not requireany special consideration with respect to function and use. Theprocedures disclosed herein with respect to the primary liquidprocessing function and the filtered liquid recovery function for filterassembly 210 apply equally to filter assembly 2610. The disclosure ofthose procedures is therefore incorporated here by reference withrespect to filter assembly 2610.

Upper end/upper end cap 2614 has additional portions defining a radiallyextending recovery port connector 2621 a that defines recovery channel2677 in fluid communication with fluid channel 2676 and with a lumen orchannel of recovery port 2622 a. An exterior surface of recovery port2622 a is formed with a pin 2622 b to receive, control and limit themovement range of an adjustable recovery port cap 2688 as disclosed inmore detail below. An internal surface of recovery port 2622 a is formedwith two differently dimensioned channels with a first outer channel2678 having a cross-sectional diameter greater than the cross-sectionaldiameter of an inner recovery port channel 2679. The junction of the twochannels may take the form of a defined annular shoulder or an annularsloped surface that joins the two differently dimensioned channels.

A recovery port valve stem 2680 dimensioned to fit within channels 2678and 2679 is substantially cylindrical in shape and has portions thatdefine a recovery port valve stem channel 2681 open at a distal end andclosed at a proximal end relative to recovery port 2622. A radiallydisposed, recovery port valve stem bore 2682 is formed toward theproximal end so as to intersect valve stem channel 2681 and provideliquid communication between channel 2681 and recovery channel lumen2677 via recovery port channels 2678 and 2679.

An outer surface of valve stem 2680 is formed with two segments havingdifferent diameters, the junction of which form an annular shoulder orbarb-like ring. A recovery valve stem proximal segment 2683 that definesat least a part of the proximal end terminus for channel 2681 has across-sectional diameter dimensioned to fit within the inner recoveryport channel 2679. A recovery valve stem distal segment 2684 has across-sectional diameter dimensioned to fit within outer recovery portchannel 2678. The transition between the two valve stem surfaces mayform a defined annular shoulder, or may be an annular sloped surfacefrom a substantially smooth transition between the two differently sizedvalve stem surfaces. A distal tip of valve stem 2680 may be formed witha barbed feature or other end modification to receive tubes, connectors,quick connects and the like.

Proximal segment 2683 has a recovery valve stem first annular channel2685 formed thereon and dimensioned to receive a first recovery valveO-ring 2686. Distal segment 2684 has a recovery valve stem secondannular channel 2687 a formed thereon and dimensioned to receive asecond recovery valve O-ring 2687. An outer surface of first valveO-ring 2686 registers against the inner wall of inner recovery portchannel 2679 to form a substantially liquid-tight seal. An outer surfaceof second valve O-Ring 2687 registers against an inner wall of outerrecovery port channel 2678 to form a substantially liquid-tight seal. Itshould be understood that the seals formed by these O-rings are meant tobe sliding seals in that the valve stem can freely move within recoveryport 2622 along a longitudinal axis of the recovery port. Valve stem2680 motion is restricted by an adjustable recovery port valve cap 2688disclosed in detail below.

In a closed position, first valve O-Ring 2686 registers against the wallof recovery port channel 2679 to form a liquid-tight seal and preventfluid and/or gas from entering or exiting the recovery port. In an openposition, first valve O-ring 2688 is positioned away from recovery portchannel 2679 (in a distal direction) so as to create a fluid path fromchannel 2677 (shown in FIG. 46), to inner recovery port channel 2679 tothe larger outer recovery port channel 2678 in through radial recoveryport valve stem bore 2682 then into valve stem channel 2681 and out (orinto) the filter assembly depending upon the direction of flow. Radialbore 2682 is positioned on the valve stem at a point or location betweenthe two O-rings so that when the valve stem is moved into any positionwithin its range of travel, liquids cannot escape between the interfaceof recovery port 2622 a and valve stem 2680.

As shown in FIGS. 59-62, adjustable recovery port valve cap 2688 has aninner wall that defines a valve cap channel 2689. The wall is formedwith a helically oriented slot 2688 a dimensioned to receive pin 2688 bthat projects into the slot from external surface of recovery port 2622a. The slot may be formed with an enlarged distal end 2688 c to providea releasable locking edge that pin 2688 b registers against when theport is in a closed condition. This helps prevent unwanted opening ofthe valve without the deliberate use of force to open the valve. Thelength of axial travel of valve stem 2680 within recovery port 2622 a isdetermined by the length of slot 2688 a with the ends of the slotfunctioning as stops that limit the length of axial travel. Opening andclosing the valve is performed by rotating cap 2688 about an externalsurface of recovery port 2622 a in either a clockwise, orcounterclockwise direction.

The cross-sectional diameter of channel 2689 is dimensioned to permitcap 2688 to fit on, and rotate freely about, the external surface ofrecovery port 2622 a. A distal end defines an annular radially inwardlyprojecting ridge or lip 2690 with a cross-sectional diameter smallerthan the cross-sectional diameter of valve cap channel 2689. An annularcap-receiving channel 2691 is formed on valve stem 2680 to receive ridge2690. Alternatively, the channel may be formed by two substantiallyparallel recovery valve stem annular rings or walls 2692 formed on theouter surface of the valve stem and spaced to receive ridge 2690.Regardless whether the channel is formed below the outer surface of thevalve stem or thereon, the cross-sectional diameter of cap-receivingchannel 2691 is smaller than the cross-sectional diameter of ridge 2690and the cross-sectional diameter of walls 2692 (or the cross-sectionaldiameter of the valve stem if the channel is formed below the outersurface of the valve stem) are greater than the cross-sectional diameterof ridge 2690.

This configuration traps the relative location of ridge 2690 and thuscap 2688 on valve stem 2680 so that rotation in either direction(clockwise, counterclockwise) of cap 2688 and its movement along theexternal surface of recovery port 2622 a via the slot and pinconfiguration causes a corresponding axial movement of the valve stem toretreat from, or advance into, recovery port 2622 a to open and closethe valve, respectively. As should be understood in the art, angularorientation of the slot on the cap can be altered to cause valve closureby turning the cap in either direction. In one orientation, rotation ofthe cap clockwise will close the valve. In a second orientation,rotation of the cap in a counterclockwise direction will close thevalve. Ridge 2690 freely rotates about valve stem 2680 and deliversaxial force to the valve stem by registering against at least theleading channel wall in the direction the cap is moved along recoveryport 2622 a. This configuration permits manual or automated control ofthe bleed valve.

Referring again to FIGS. 41, 42, 46 and now also to FIGS. 47, 48, 53 and54, upper end/upper end cap 2614 has further additional portions thatdefine an axially extending upstream vent channel 2651 that defines alumen in fluid communication with upstream volume 2634 and with a lumenof an upstream vent port 2624 a. An exterior surface of upstream ventport 2624 a is formed with a pin 2705 to receive, control and limit themovement range of an adjustable upstream vent cap 2652 as disclosed inmore detail below. An internal surface of upstream vent port 2624 a isformed with two differently dimensioned channels with a first outer ventchannel 2653 having a cross-sectional diameter greater than thecross-sectional diameter of a second inner vent channel 2654. Thejunction of the two channels may take the form of a defined annularshoulder or an annular sloped surface that joins the two differentlydimensioned channels.

An upstream vent port valve stem 2655 dimensioned to fit within ventchannels 2653 and 2654 is substantially cylindrical in shape and hasportions that define a vent port valve stem channel 2656 open at adistal end and closed at a proximal end relative to vent port 2624 a. Aradially disposed, vent port valve stem bore 2657 is formed toward theproximal end so as to intersect valve stem channel 2656 and provideliquid communication between channel 2656 and a lumen of vent portchannel 2651 (shown in FIG. 46).

An outer surface of valve stem 2655 is formed with two segments havingdifferent diameters, the junction of which forms an annular shoulder orbarb-like ring. A vent valve stem proximal segment 2658 that defines atleast a part of the proximal end terminus for channel 2656 has across-sectional diameter dimensioned to fit within inner vent portchannel 2654. A vent valve stem distal segment 2659 has across-sectional diameter dimensioned to fit within outer vent portchannel 2653. The transition between the two valve stem surfaces mayform a defined annular shoulder, or may be an annular sloped surface tofrom a substantially smooth transition between the two differently sizedvalve stem surfaces. A distal tip of vent valve stem 2655 may be formedwith a barbed feature or other end modification to receive tubes,connectors, quick connects and the like.

Vent valve stem proximal segment 2658 has a vent valve stem firstannular channel 2660 formed thereon and dimensioned to receive a firstvent valve O-ring 2661. Vent valve stem distal segment 2659 has a ventvalve stem second annular channel 2662 formed thereon and dimensioned toreceive a second vent valve O-ring 2663. An outer surface of first valveO-ring 2661 registers against the inner wall of inner vent port channel2654 to form a substantially liquid-tight seal. An outer surface ofsecond valve O-Ring 2663 registers against an inner wall of outer ventport channel 2653 to form a substantially liquid-tight seal. It shouldbe understood that the seals formed by these O-rings are meant to besliding seals in that the valve stem can freely move within vent port2624 a along a longitudinal axis of the vent port. Vent valve stem 2655motion within the vent port is restricted by adjustable vent port valvecap 2652 disclosed in detail below.

In a closed condition as shown in FIG. 47, first valve O-ring 2661registers against the wall of inner vent port channel 2654 to form aliquid-tight seal and prevent fluid and/or gas from entering or exitingthe vent port. In an open condition, first valve O-ring 2661 is awayfrom vent port channel 2654 (in a distal direction) so as to create afluid path from vent channel 2651 to inner vent port channel 2654 to thelarger outer vent port channel 2653 in through radial vent port valvestem bore 2657 then into valve channel 2656 and out (or into) the filterassembly depending upon the direction of flow. It should be noted thatradial bore 2657 is positioned between the two O-rings so that in anyvalve stem position, liquids cannot escape between the interface of ventport 2624 a and vent port valve stem 2655.

Adjustable upstream vent port valve cap 2652 has an inner wall thatdefines a valve cap channel 2665. The wall is formed with a helicallyoriented slot 2704 dimensioned to receive pin 2705 that projects intothe slot from the external surface of vent port 2624 a. The slot may beformed with an enlarged distal end 2706 to provide a releasable lockingedge that pin 2705 registers against when the port is in a closedcondition. This helps prevent unwanted opening of the valve without thedeliberate use of force to open the valve. The length of axial travel ofvalve stem 2673 within vent port 2624 a is determined by the length ofslot 2704 with the ends of the slot functioning as stops that limit thelength of axial travel. Opening and closing the valve is performed byrotating cap 2652 about the external surface of vent port 2624 a ineither a clockwise, or counterclockwise direction.

The cross-sectional diameter of channel 2665 is dimensioned to permitcap 2652 to fit on, and rotate freely about, the external surface ofvent port 2624 a. A distal end defines an annular radially inwardlyprojecting ridge or lip 2666 with a cross-sectional diameter smallerthan the cross-sectional diameter of valve cap channel 2665. An annularcap-receiving channel 2667 is formed on valve stem 2655 to receive ridge2666. Alternatively, the channel may be formed by two substantiallyparallel annular vent valve stem rings or walls 2668 formed on the outersurface of the valve stem and spaced to receive ridge 2666. Regardlesswhether the channel is formed below the outer surface of the valve stemor thereon, the cross-sectional diameter of cap-receiving channel 2667is smaller than the cross-sectional diameter of ridge 2666 and thecross-sectional diameter of walls 2668 (or the cross-sectional diameterof the valve stem if the channel is formed below the outer surface ofthe valve stem) are greater than the cross-sectional diameter of ridge2666.

This configuration traps the relative location of ridge 2666 and thuscap 2652 on valve stem 2655 so that rotation in either direction(clockwise, counterclockwise) of cap 2652 and its movement along theexternal surface of vent port 2624 a via the slot and pin configurationcauses a corresponding axial movement of the valve stem to retreat from,or advance into, vent port 2624 a to open and close the valve,respectively. Ridge 2666 freely rotates about valve stem 2655 anddelivers axial force to the valve stem by registering against at leastthe leading channel wall in the direction the cap is moved along theexternal surface of vent port 2624 a. This configuration permits manualor automated control of the vent port bleed valve.

Referring again to FIGS. 41, 42, 46 and now also to FIGS. 55 and 56,lower end/lower end cap 2616 has portions that define a radiallyextending upstream drain channel 2669 that defines a lumen in fluidcommunication with upstream volume 2634 and with a lumen or channel 2664of upstream drain port 2626 a. Channel 2664 may have a slight conicalshape or tapered shape in cross-section with the larger end of the taperextending toward the distal end of the drain port as shown in FIGS. 55and 56. This configuration permits increased fluid flow through the portwith increased opening of the port. An exterior surface of upstreamdrain port 2626 a is formed with threading 2708 to receive an adjustableupstream drain cap 2671 as disclosed in more detail below. Thecross-sectional diameter of the drain port channel 2664 is greater thanthe cross-sectional diameter of drain channel 2669.

An upstream drain port valve stem 2673 dimensioned to fit within drainport channel 2664 is substantially cylindrical in shape and has portionsthat define a drain port valve stem channel 2693 open at a distal endand closed at a proximal end relative to drain port 2626 a. A radiallydisposed, drain port valve stem bore 2694 is formed toward a proximalend of channel 2693 so as to intersect channel 2693 and provide fluidcommunication between channel 2693 and drain channel 2669 via drain portchannel 2664. An outer surface of valve stem 2673 is formed with twosegments having different diameters, the junction of which creates anannular shoulder or barb-like ring. A drain valve stem proximal segment2695 has a cross-sectional diameter dimensioned to be smaller than thecross-sectional diameter of drain port channel 2664 so as to form anannular gap between the surfaces. A drain valve stem distal segment 2696that defines at least a part of the proximal end terminus for channel2693 has a cross-sectional diameter dimensioned to fit more snuglywithin the drain port channel (at the smallest diameter of the taper),so as to form a smaller annular gap relative to the gap formed byproximal segment 2695 and channel 2664. The transition between the twovalve stem surfaces may form a defined annular shoulder, or may be anannular sloped surface to from a substantially smooth transition betweenthe two differently sized valve stem surfaces.

A proximal tip 2699 of drain port valve stem 2673 is conical in shapeand functions like a needle valve. Movement of valve stem 2673 towardchannel 2669 causes an extreme proximal end of conical tip 2699 to enterinto channel 2669 until the conical surface registers against theannular leading edge of the channel (that functions as a valve seat) soas to occlude the channel lumen and prevent any egress or ingress ofliquids and/or gases out of, or into, the filter assembly. An oppositedistal tip of drain port valve stem 2673 may be formed with a barbedfeature or other end modification to receive tubes, connectors, quickconnects and the like.

Drain valve stem distal segment 2696 has a drain valve stem annularchannel 2697 formed thereon and dimensioned to receive a drain valveO-ring 2698. An outer surface of drain valve O-ring 2698 registersagainst the lumen wall of the drain port channel to form a substantiallyliquid-tight seal. It should be understood that the seal formed by thisO-ring is meant to be a sliding seal in that the valve stem can freelymove within drain port 2626 a along a longitudinal axis of the drainport without compromising the seal function of the O-ring. Drain valvestem 2673 motion within the port is restricted by adjustable drain portvalve cap 2671 disclosed in detail below.

As stated, in a closed condition as shown in FIG. 56, conical tip 2699registers against the annular leading edge of drain channel 2669 to forma liquid-tight seal and prevent fluid and/or gas from entering orexiting the drain port. In an open condition as shown in FIG. 55,conical tip 2699 is away from drain channel leading edge (in a distaldirection) so as to create a fluid path from drain channel 2669 to drainport channel 2664 through radial drain port valve stem bore 2694 theninto drain valve stem channel 2693 and out (or into) the filter assemblydepending upon the direction of flow. It should be noted that radialbore 2694 is positioned proximal to the filter assembly relative toO-ring 2698 so that in any position, liquids cannot escape from thefilter assembly between the interface of drain port 2624 a and drainport valve stem 2673.

Adjustable upstream drain port valve cap 2671 has an inner wall thatdefines a drain valve cap channel 2700. The inner wall is formed withthreading 2707 to mate with threading 2708 of drain port 2626 a. Thecross-sectional diameter of channel 2700 is dimensioned to permit cap2671 to fit on, and rotate freely about, drain port 2626 a. A distal enddefines an annular radially inwardly projecting ridge or lip 2701 with across-sectional diameter smaller than the cross-sectional diameter ofvalve cap channel 2700. An annular cap-receiving channel 2702 is formedon valve stem 2673 to receive ridge 2701. Alternatively, the channel maybe formed by two substantially parallel annular drain valve stem ringsor walls 2703 formed on the outer surface of the valve stem and spacedto receive ridge 2701. Regardless whether the channel is formed belowthe outer surface of the valve stem or thereon, the cross-sectionaldiameter of cap-receiving channel 2702 is smaller than thecross-sectional diameter of ridge 2701 and the cross-sectional diameterof walls 2703 (or the cross-sectional diameter of the valve stem if thechannel is formed below the outer surface of the valve stem) are greaterthan the cross-sectional diameter of ridge 2701.

This configuration traps the relative location of ridge 2701 and thuscap 2671 on valve stem 2673 so that rotation in either direction(clockwise, counterclockwise) of cap 2671 and its movement along drainport 2626 a via the mated threading causes a corresponding movement ofthe valve stem to retreat from, or advance into, drain port 2626 a toopen and close the valve, respectively. Ridge 2701 freely rotates aboutvalve stem 2673 and delivers axial force to the valve stem byregistering against at least the leading channel wall in the directionthe cap is moved along drain port 2626 a. This configuration permitsmanual or automated control of the vent port bleed valve.

Alternative constructions to secure the filter element to the filterassembly housing are shown in FIGS. 50-52, 57 and 58. As shown in FIGS.50 and 57, a liquid recovery filter assembly shown designated generallyas 2810 includes features corresponding to most of the features shownand disclosed for the other previously disclosed embodiments.

Filter assembly 2810 includes a housing or shell 2811 constructed from ashell wall 2812, upper end/end cap 2814, lower end/end cap 2816, thecombination of which define an internal volume designated generally as2828. The filter assembly has ports corresponding to the ports of theother disclosed filter assembly embodiments: an inlet port 2818, anoutlet port 2820, a recovery port 2822, a vent port 2824, an upstreamdrain port 2826, and encloses a corresponding filter element designatedgenerally as 2830 constructed in this embodiment as a filter cartridgethat encloses a plurality of hollow fibers 2830 a. An upstream volume2834 is defined by filter housing 2811 and the collective upstreamdesignated surfaces of hollow fibers 2830 a. Hollow fibers 2830 a eachdefine a downstream core 2832. Cores 2832 are in fluid communicationwith a downstream collection space 2832 a defined by a filter elementlower end cap 2830 c and a hollow fiber lower end cap 2837 a disclosedin more detail below. Space 2832 a is in fluid communication with outletport 2820.

More specifically, filter cartridge 2830 includes a cage wall 2831 withopenings 2837 b, a cartridge upper end cap designated generally as 2830b and lower end cap 2830 c. The end caps may be formed from the samematerial used for the cage wall (as well as for the filter assemblyhousing). A hollow fiber upper end cap 2837 and a hollow fiber lower endcap 2837 a may be formed as potting layers constructed from a urethaneor epoxy adhesive or like material with a series of openings to permitfluid communication with the downstream cores of the individual hollowfibers. Alternatively, a hollow fiber upper end cap 2837 and a hollowfiber lower end cap 2837 a may also be formed from thermal plasticmaterials by thermally melting and potting the materials to the hollowfibers. This method is particularly advantageous for hollow fibermaterials that are notably hard to adhere with adhesives, e.g., PTFE,PFA/MFA, PVDF and HDPE as disclosed in more detail herein.

Filter cartridge 2831 is secured to housing designated generally as 2811via features formed on the upper and lower cartridge ends/end caps. Anupper cartridge sleeve 2843 extends upwardly from upper cartridge endcap 2830 b and is dimensioned to receive a lower post 2878 a of arecovery filter assembly 2823 similar to the post/sleeve combinationshown in FIG. 49. An annular (or other shape) recovery filter lower postchannel 2880 a is formed on lower post 2878 a. A cartridge upper endO-ring 2882 is positioned between the sleeve and post and is secured inlower post channel 2880 a in similar fashion to the sleeve and postconfiguration disclosed for recovery filter assembly 2623 shown in FIGS.46 and 49. The upper end of recovery filter assembly 2823 is secured toupper end/end cap 2814 in the same manner and with the same options asdisclosed for recovery filter assembly 2623 shown in FIGS. 46 and 49.

A lower cartridge post 2833 is dimensioned to fit within outlet port2820 and defines a lumen in fluid communication with outlet port 2820and downstream collection space 2832 a. An annular O-ring channel 2839is formed in the outer wall of post 2833 to receive and secure acartridge lower end O-ring 2841 used to seal the registered surfaces.Alternatively, lower cartridge post 2833 may be secured to outlet port2820 via thermal or sonic bonding, adhesives, combinations of thebonding methods and the like. These alternative bonding methodseliminate the need for O-ring 2841 and any features specific to anyembodiment using an O-ring to create a seal between the lower cartridgepost and the outlet port.

The components of filter assembly 2810 are constructed from the samematerials disclosed for the other disclosed embodiments. Filter assembly2810 is operated in the same manner as disclosed for filter assembly 210as well as the other disclosed embodiments. The operation proceduresdisclosed for filter assembly 210 are incorporated here with respect tofilter assembly 2810. By way of illustration, and not by way oflimitation, the hollow fiber material may be constructed from materialsselected from the group consisting of polyethersulfone (PES),polysulfone (PS), Nylon 6, Nylon 66, regenerated cellulose, mixed estersof cellulose, polycarbonate, polyester, polyacrylonitrile (PAN),polyimide, polyamide, and mixtures thereof. The hollow fiber materialmay also be constructed from materials selected from the groupconsisting of virgin or surface modified expandedPolytetrafluoro-ethylene (Teflon® PTFE) with or without lamination,phase inversion formed polyvinylidene fluoride (PVDF), perfluoroalkoxy(PFA) and its derivatives, Ethylene-clorotrifluoroethylene copolymer(ECTFE), polypropylene (PP), high density polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMWPE or UPE) and mixtures thereof.Inorganic materials that may be used include ceramics including alumina,zirconia and sintered stainless steel. The inner and outer diameters ofthe hollow fibers can vary widely as is well known and available in theart, depending upon the specific filtration applications, and can rangefrom about 100 microns to millimeters. It should be understood thatother filter materials disclosed herein and/or well known in the art maybe substituted for the hollow fiber filter material and remain withinthe scope of the disclosure.

Referring now to FIG. 51, in another aspect of the disclosure, anotheralternative configuration to secure a filter element in the form of afilter cartridge in a filter housing is shown. A liquid recovery filterassembly shown designated generally as 2910 includes featurescorresponding to most of the features shown and disclosed for the otherpreviously disclosed embodiments.

The features of filter assembly 2910 that correspond to the features ofthe other disclosed embodiments include a housing or shell designatedgenerally as 2911 constructed from a shell wall 2912, an upper end/endcap 2914, a lower end/end cap 2916, the combination of which define aninternal volume designated generally as 2928. The filter assembly hasports corresponding to the ports of the other disclosed embodiments: aninlet port 2918, an outlet port 2920, a recovery port 2922, a vent port2924, an upstream drain port 2926, and encloses a corresponding filterelement designated generally as 2930 constructed in this embodiment as afilter cartridge that encloses a plurality of hollow fibers 2930 a. Anupstream volume 2934 is defined by filter housing 2911 and thecollective upstream designated surfaces of hollow fibers 2930 a. Hollowfibers 2930 a each define a downstream core 2932. Cores 2932 are influid communication with a downstream collection space 2932 a defined bya filter element lower end cap 2937 a and lower end/end cap 2916. Space2932 a is in fluid communication with outlet port 2920.

More specifically, filter cartridge 2930 includes a cage wall 2931 withopenings 2937 b, a cartridge upper end/end cap 2930 b and lower end/endcap 2937 a. The end caps may be formed from the same material used forthe cage wall (as well as for the filter assembly housing). A hollowfiber upper end cap 2937 and lower end cap 2937 a may be formed aspotting layers constructed from a urethane adhesive or like materialwith a series of openings to permit fluid communication with thedownstream cores of the individual hollow fibers.

Filter cartridge 2931 is secured to housing 2911 via features formed onthe upper and the lower cartridge ends/end caps. The upper end of filtercartridge 2931 is secured to a recovery filter assembly 2923 with thesame construction and in the same manner as disclosed for filtercartridge 2831. The disclosure with respect to the attachment of theupper end of filter cartridge 2831 and any disclosed alternatives isincorporated here with respect to attachment of the upper end of filtercartridge 2931. The components of filter assembly 2910 that correspondto the components of filter assembly 2810 are identified by substitutinga “9” for the second digit “8” with respect to the reference charactersused to call out the components of filter assembly 2810.

The lower end of filter cartridge 2930 is secured to housing 2911 bythermally bonding a lower end/end cap 2937 a to shell wall 2912. The endcaps may also be bonded to the shell wall via sonic welding, adhesiveand the like. The end caps may be formed from the same materials usedfor the cage wall (as well as for the filter assembly housing).Alternatively, a hollow fiber upper end cap 2937 and lower end cap 2937a may be formed as potting layers constructed from a urethane adhesiveor like material with a series of openings to permit fluid communicationwith the downstream cores of the individual hollow fibers.

The components of filter assembly 2910 are constructed from the samematerials disclosed for the other disclosed embodiments. Filter assembly2910 is operated in the same manner as disclosed for filter assembly 210as well as the other disclosed embodiments. The operation proceduresdisclosed for filter assembly 210 are incorporated here with respect tofilter assembly 2910.

Referring now to FIG. 52, in another aspect of the disclosure, a furtheralternative configuration to secure a filter element in the form of afilter cartridge in a filter housing is shown. A liquid recovery filterassembly shown designated generally as 3010 includes featurescorresponding to most of the features shown and disclosed for the otherpreviously disclosed embodiments with the noted exception of the absenceof a recovery filter. It should be understood a recovery filter will beattached to whichever port is designated as a recovery port so as toperform the intended liquid recovery function of the disclosure.

The filter assembly features corresponding to the features of the otherdisclosed embodiments includes a housing or shell designated generallyas 3011 constructed from a shell wall 3012, an upper end/end cap 3014, alower end/end cap 3016, the combination of which define an internalvolume designated generally as 3028. The filter assembly has portscorresponding to the ports of the other disclosed embodiments: an inletport 3018, an outlet port 3020, a recovery port 3022, a vent port 3024,an upstream drain port 3026, and encloses a corresponding filter element3030 in the form of a filter cartridge constructed with a plurality ofhollow fibers or tubular membranes 3030 a. Filter assembly 3010 differsfrom filter assemblies 2810 and 2910 with respect to the means used tosecure the filter element in the housing.

Filter cartridge 3030 includes a cage wall 3031 with openings 3037 b, acartridge upper end/end cap 3030 b and a cartridge lower end/end cap3030 c. An upstream volume 3034 is defined by filter housing 3011 andthe collective upstream designated surfaces of hollow fibers 3030 a.Hollow fibers 3030 a each define a downstream core 3032. Cores 3032 arein fluid communication with a downstream collection space 3032 a definedby filter element lower end cap 3030 c and a hollow fiber lower end cap3037 a disclosed in more detail below. Space 3032 a is in fluidcommunication with outlet port 3020.

The cage and end caps may be formed from the same materials disclosedfor the components of the other disclosed filter assembly embodiments.The hollow fibers (described in detail with respect to filter assembly2810) may have additional end caps to secure the hollow fibers incartridge 3030. A hollow fiber upper end cap 3037 and a hollow fiberlower end cap 3037 a may be formed as potting layers constructed from aurethane adhesive or like material with a series of openings to permitfluid communication with the downstream cores of the individual hollowfibers.

Filter cartridge 3031 is secured to housing 3011 via features formed onthe upper and lower cartridge ends/end caps. To secure the upper end ofthe cartridge, a cartridge upper post 3043 a extends upwardly fromcartridge upper end cap 3030 b and is dimensioned to fit within ahousing upper end/end cap sleeve 3015. A cartridge upper end O-ring 3043b positioned therebetween is secured in an annular (or other shape)upper post channel 3043 c formed in the outer wall of post 3043 a insimilar fashion to the sleeve and post configuration disclosed forrecovery filter 2623 shown in FIG. 46. Like the embodiment shown in FIG.46, the post and sleeve configuration can be reversed with the sleeveformed on the cartridge and the post extending downwardly from thehousing upper end/end cap.

To secure the lower end of the cartridge, a cartridge lower post 3033extends downwardly from cartridge lower end cap 3030 c and isdimensioned to fit within outlet port 3020. Post 3033 defines a lumen influid communication with port 3020 and downstream collection space 3032a. An annular (or other shape) O-ring channel 3039 is formed in theouter wall of post 3033 to receive and secure a cartridge lower endO-ring 3041 used to seal the registered surfaces.

The components of filter assembly 3010 are constructed from the samematerials disclosed for the other disclosed embodiments. Filter assembly3010 is operated in the same manner as disclosed for filter assembly 210as well as the other disclosed embodiments. The operation proceduresdisclosed for filter assembly 210 are incorporated here with respect tofilter assembly 3010.

Referring now to FIG. 58, another embodiment of filter assembly 2810 isshown. A filter assembly shown designated generally as 3110 has the samefeatures disclosed for filter assembly 2810. The components of filterassembly 3110 that correspond to the components of filter assembly 2810are identified by substituting a “30” for the first and second digits“28” with respect to the reference characters used to call out thecomponents of filter assembly 2810. Filter assembly 3110 differs fromfilter assembly 2810 in the distribution and density of hollow fiberssecured in the filter cartridges. Filter assembly 3110 has a greaterdensity of hollow fibers than filter assembly 2810.

Referring now to FIGS. 43-45, in a further aspect of the disclosure,line clearing filter assemblies are shown designated generally as 2710and include features to permit the recovery of filtered liquids in linesdownstream of a filter assembly as well as liquids in other lines orprocessing equipment where it is necessary to prevent the contaminationof the liquids contained therein. This can be used alone, or incombination with the recovery filter for the filter assembly to whichthe downstream line(s) is/are attached.

A recovery port 2742 is connected to, and extends from, process fluidpathway 2780. Recovery filter 2743 is secured in-line with recovery port2742 and houses recovery filter material 2725. In the followingdescription of the embodiments shown designated generally as 2710, theterm “downstream” is used to refer to locations, components, fluids,etc. located on the same side of recovery filter material 2725 asprocess fluid pathway 2780 and the term “upstream” is used to refer tolocations, components, fluids, etc. located on the opposite side ofrecovery filter material 2725 and process fluid pathway 2780.

Recovery filter 2743 and recovery filter material 2725 are designed andsituated such that all fluid passing between the upstream and downstreamside must pass through the recovery filter material 2725. Recoveryfilter material 2725 is chosen to have the appropriate properties asdisclosed previously for recovery filter 223. Process line adaptors 2782allow connection of the line clearing filter 2710 to tubing, processingequipment, filters, filter assemblies, or other assemblies andcomponents commonly used to transfer and perform unit operations onfluids. The embodiments shown in FIGS. 43 through 45 all show barbedadapters 2782 for connecting to tubing; however, other adapter typessuch as threaded connections, sanitary fittings, quick connects, luerfittings, as well as any other method for attaching filters disclosedherein as well as any other method for attaching filters as is known inthe art may be used.

The process line adaptors are chosen to allow each end of the lineclearing filter to connect to the desired components as disclosedpreviously, and therefore, each adaptor does not have to be of the sametype. Further, embodiments with more than two adapters are possible andare within the consideration and scope of this disclosure. Process fluidpathway 2780 is in liquid communication with process line adaptors 2782and in fluid communication with recovery port 2742, such that the flowof fluids from one process line adaptor 2782 to a second process lineadaptor as well as flow from any process line adaptor to the downstreamportion of recovery port 2742 is unobstructed. Further, flow of fluidsfrom process line adaptor 2782 to the upstream portion of recovery port2742 is only possible for fluids that are capable of passage throughrecovery filter material 2725. Recovery port adapter 2720 allows forconnection to recovery port 2742 in a similar manor to process lineadaptor 2782 and may be a barbed fitting, threaded connection, sanitaryfitting, quick connect, luer fitting, as well as any other method forattaching filters disclosed herein as well as any other method forattaching filters as is known in the art may be used.

Optional upstream valves 2786 as shown in FIGS. 44 and 45 are used tocontrol the flow into or out of the recovery port 2742 and can be of anysuitable type (e.g., needle, ball, etc.) disclosed herein or anysuitable type known in the art. Optional valve 2788 as shown in FIG. 45can be used to control the flow into or out of the recovery port 2742and has the additional capability of protecting recovery filter 2723from exposure to fluids contained in process fluid pathway 2780 orlimiting exposure.

When installed onto tubing, processing equipment, filters, filterassemblies, or other assemblies and components, the line clearing filterassembly can be used to clear lines of liquids resident in thesecomponents by the application of pressurized gas at the upstream side ofrecovery port 2742. With optional valves 2786 and 2788 opened, ifpresent, gas travels into the process fluid pathway 2780, and clearsliquid in its path. The direction of the gas flow, once within theprocess fluid pathway 2780, can be controlled by way of valves, or canbe allowed to flow freely dependent on the application.

When used downstream of a filter assembly, particularly those withoutthe liquid recovery features disclosed herein, the flow will primarilybe in the direction away from the filter assembly, clearing lines andcomponents further downstream, as gas cannot flow through the filter'sprocessing membrane. However, when appropriately positioned, the lineclearing filter may be used to introduce gas into the outlet ordownstream port of the filter assembly, displacing resident liquidtherein, thus providing a means of recovering the potentially valuableliquid.

The use of optional valve 2788 is particularly beneficial whereprocessing fluid contained within process fluid pathway 2780 can (due tohigh pressures or due to the surface tension and surface energies of theprocessing fluid and the recovery filter material respectively) wet-outthe recovery filter material 2725. Allowing the recovery filter material2725 to wet-out can block the flow of gases through the filter material2725 thus reducing or impeding its ability to clear lines.

Accordingly, the various embodiments of the disclosed liquid recoveryfilter apparatus provide an effective means to recover costly liquidsused in filtering operations particularly in the pharmaceutical as wellas in other industries. It should be understood that the various axialand radial configurations of the various inlet and outlet passages orports illustratively depicted in the drawings and disclosed herein aremerely exemplary, and that various other arrangements of these ports orpassages are within the contemplation and scope of the disclosure thatprovide a means for the drainage or removal of liquid from the filterhousing or shell wall, and particularly for the drainage or removal offiltered liquid from the core of the filter.

The present disclosure is not limited to the embodiments disclosedherein, but encompasses any and all embodiments and equivalents thereofwithin the scope of the following claims.

What we claim as new and desire to secure by Letters Patent is:
 1. Aliquid recovery filter assembly comprising: a filter assembly housinghaving a shell wall with an upper end cap and a lower end cap, whereinthe upper end cap and the lower end cap are secured to the shell wall,and wherein the combination of the shell wall and the end caps define aninternal volume; at least one processing filter defining a filter coresecured in the housing and occupying a portion of the internal volume,wherein an upstream volume is defined by the filter assembly housing andan upstream designated surface of the at least one processing filter andwherein the filter core defines a downstream side of the at least oneprocessing filter; an aspiration tube secured to, or formed with, thefilter housing, wherein the aspiration tube extends at least partiallyinto the filter core at one end and extends out of the filter housing ata second end, wherein the aspiration tube has at least one openingpositioned within the filter core to permit fluid communication betweenthe aspiration tube and the filter core so as to permit the introductionof a sterile gas from the aspiration tube into the downstream side ofthe at least one processing filter to purge and recover filtered fluidsretained in the downstream side of the at least one processing filterafter a filtration procedure; a recovery filter secured in-line with theaspiration tube, wherein the recovery filter is in fluid communicationwith the filter core; an inlet port extending from the housing in fluidcommunication with the upstream volume; and, an outlet port extendingfrom the housing in fluid communication with the filter core.
 2. Theliquid recovery filter assembly of claim 1 further comprising anupstream vent port extending from the filter housing, wherein the ventport is in fluid communication with the upstream volume.
 3. The liquidrecovery filter assembly of claim 2 further comprising an upstream ventport valve secured in-line with the vent port.
 4. The liquid recoveryfilter assembly of claim 3 further comprising an aspiration tube valvesecured in-line with the aspiration tube on a side of the recoveryfilter distal from the filter assembly housing.
 5. The liquid recoveryfilter assembly of claim 1 wherein the assembly comprises a plurality ofprocessing filters secured in the housing, wherein each processingfilter defines a filter core, and wherein the assembly further comprisesa plurality of aspiration tubes, wherein each processing filter of theplurality of processing filters has a dedicated aspiration tubeextending at least partially into the core of each processing filter atone end and extending outwardly from the filter housing at a second end.6. The liquid recovery filter assembly of claim 5 further comprising aplurality of recovery filters each secured in-line with one aspirationtube, whereby each aspiration tube has a single recovery filter attachedthereto.
 7. The liquid recovery filter of claim 6 wherein eachaspiration tube has a dedicated aspiration tube valve secured thereto ona side of the attached recovery filter distal from the filter assemblyhousing.
 8. The liquid recovery filter assembly of claim 5, wherein theplurality of aspiration tubes are joined at distal ends with anaspiration tube manifold, wherein the aspiration tubes are in fluidcommunication with the manifold.
 9. The liquid recovery filter assemblyof claim 8 further comprising a plurality of recovery filters, whereineach recovery filter is secured in-line with one aspiration tube,wherein each aspiration tube has a single recovery filter securedthereto.
 10. The liquid recovery filter assembly of claim 8 furthercomprising a manifold extension tube in fluid communication with themanifold and the plurality of aspiration tubes and further comprising atleast one recovery filter secured to the manifold extension.
 11. Theliquid recovery filter assembly of claim 10 further comprising amanifold extension tube valve secured to the extension tube on a side ofthe recovery filter distal from the filter assembly housing.
 12. Theliquid recovery filter of claim 4 further comprising a recovery portsecured in-line with the recovery filter and the aspiration tube,separate from the outlet port, wherein the recovery port is in fluidcommunication with the recovery filter, the aspiration tube and thefilter core.
 13. The liquid recovery filter of claim 1 furthercomprising a recovery port secured in-line with the recovery filter andthe aspiration tube, separate from the outlet port, wherein the recoveryport is in fluid communication with the recovery filter, the aspirationtube and the filter core.